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20091238776Line breaks have only been retained for non-prose elements.Geological and other ReportsHon. J. Coutts Crawford81 pp.1862Source copy consulted: National Library of New Zealand, MS-Papers-1001-052
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Council paper.Province of Wellington.Geological and Other Reports, by the Hon. J. Coutts Crawford.
Wellington, October 24, 1861.
Sir,—At a time when considerable interest is felt with regard to the mineral resources of the Colony and Province, I have the honor to report the results of a geological tour which I have lately made in the Wairarapa and East Coast country, in the hope that my observations may be of some interest to yourself and to the public.
As a preliminary, it is necessary to make my remarks intelligible, that I should tabulate the rocks already known to exist in the above named tract of country; and having been kindly favored by Mr. Triphook of Napier, about two years ago, with a geological section of the rocks in the Province of Hawke, it will be desirable first to put down his list, as the same series of rocks extends to the country I propose to describe, and then to add to them those rocks which I have discovered.
Mr. Triphook's list of rocks in the Province of Hawke, in a descending series—
Tertiary.
Fossiliferous limestone, marine fossils, 500 to 800 feet thick.
Crystalline sandstone gravel waterworn, unfossiliferous, 300 to 500 feet thick.
Seam of lignite (9 inches thick.)
Argillaceous indurated shale, fossiliferous.
Metamorphic or altered rock, probably Silurian.
Hard, green, gritty sandstone, unfossiliferous.
With the exception of the nine-inch seam of lignite (which I have heard rumours of in the Wairarapa, but have not seen) all the above named rocks extend to this part of the island.
The additions I propose to make to Mr. Triphook's series are—
Recent formations.—Deposit of travertin formed and still forming at various points on the east side of the Wairarapa, from streams charged with carbonate of lime. This deposit may be particularly remarked at Mr. M‘Masters’ station, Te Pura Pura, where I found some beautiful specimens of encrusted ferns. I also observed the same formation at Hautotara.
A raised beach extending round the coast.
I next propose to divide the tertiary gravel into two strata, to facilitate their description. An upper stratum of coarse gravel and an under stratum of fine light red gravel. The latter may be seen capping the argillaceous shale between Wangamoana and Tekopi, and both gravels are found above the shale on a river terrace at Hautotara. Where the coarse gravel forms the surface of the ground, which it does in some parts to a great extent, the soil is naturally poor.
The next addition is a series of stratified rocks, composed of flagstones, limestones, &c., which I first found resting, highly inclined, on the flanks of the metamorphic rocks, between Mr. Barton's station and Teawaiti (Mr. Riddiford's). These rocks are of totally different mineralogical character from the tertiaries already mentioned; but as I was unable to detect any fossils in them, during a cursory search, interrupted by rain, a further investigation will be necessary to form an opinion as to their geological age. To the north of Teawaiti, I observed these rocks dipping from an anticlinal axis both inland and seaward; and on one range alone I counted five different strata, each of great thickness, inclined and showing a bold serrated edge against the sky as the point of each stratum projected. These rocks ought to be carefully examined to ascertain their age and character, and as I found indications of coal, viz., a very thin seam of that mineral, in a conglomerate rock of the series, it is just possible that we may here find the representatives of the carboniferous rocks lately discovered by Mr. Haast in the Province of Canterbury. There is every reason to suspect that this series will prove to be either secondary or palæozoic. On a line parallel to the East Coast, and perhaps at a distance of ten miles from it, a number of precipitous and jagged summits are found. These hills are called taipos by the natives, and are, I am told, held in superstitious dread, as the supposed dwelling places of evil spirits. They seem to be composed of stratified and tilted sandstones, although we may find that they are broken into by igneous rocks.
The last addition which I would make at present to the list of rocks is of great geological interest. It is a true igneous rock, a hornblendic rock, which I found on Mr. Beethams' run, not in situ, but in fragments in the bed of the Upoko Ngaruru; from the decomposition of this rock ironsand is deposited, and in it Mr. Haast has discovered a speck of gold with the microscope. I would here mention that a fossil cetacean is to be seen in the bed of the Upoko Ngaruru, washed out of the argillaceous shale, and that as the floods are rapidly destroying all traces of it, it would be worth the attention of the Provincial Government to secure for the Museum as much of the skeleton as now remains.
The hornblendic rock of the Upoko Ngaruru I believe to be the first igneous rock yet discovered in the Province of Wellington, exclusive of those rocks of the Taupo country, whose pebbles are brought down the Whanganui and adjacent rivers.
Having added the above mentioned rocks to our series, I will now give a table of the rocks from Wellington to the East Coast, premising that it must be open to amendment or addition as the progress of observation and discovery proceeds.
Tabular view of strata from Wellington to the East Coast, in a descending series:—
Recent.
Travertin—Found at Te Pura Pura, Hautotara, and other points on the eastern side of the Wairarapa valley.
Raised beach—Extending round the coast. This we may venture to call “recent,” subject to future correction.
Tertiary.
Fossiliferous limestone—Found on Maungaraki range, at Hautotara and other parts of the Eastern Coast range.
Coarse crystalline sandstone gravel, unfossiliferous—Largely developed in the Wairarapa, and on the western slope of the East Coast ranges.
Fine red gravel—Seen at Wangamoana, Hautotara, &c.
Indurated clay, fossiliferous.—Perhaps the name should be shortened into “blue clay.”—Exposed at Wangamoana, and very extensively found in the East Coast ranges—Contains the cetacean of Upoko Ngaruru, marine shells, imbedded trees, &c.
Possibly secondary or palæozoic.
Series of stratified rocks of the East Coast.—Found highly inclined on the East Coast.
Probably silurian.
Metamorphic or altered rocks.—These form the Rimutaka and Tararua ranges, including all the mountainous country round Wellington, rocks extending northward from Cape Palliser, &c.
Plutonic.
Hornblendic Rock.—Found in the bed of the Upoko Ngaruru, one of the sources of the Pahaua.
To sum up—The metamorphic rocks fill a large area at the base of the series. They compose the Rimutaka and Tararua ranges, with all their spurs and offshoots as far as is yet known; they appear again cropping out on the hills on Mr. Bidwill's run, where there is probably a line of fault; they are seen between Wangamoana and Tekopi, underlying the tertiary clay; and to the eastward of Mr. murcha's homestead they rise into mountains presenting their hard surface at Cape Palliser as a buttress against the sea, and apparently there forming the mass of the mountains for a considerable distance to the northward. Whatever metals may be found in this part of the country will doubtless belong to the metamorphic rocks (except perhaps ironsand). As specimens of native copper appear to have been found in the East Coast range, a search for ores of copper in any of the metamorphic rocks may prove successful. The rocks of Cape Palliser appear to be identical with those of the main range, therefore if gold is found in one range, it may be expected in the other.
The stratified rocks of the East Coast may be searched for coal and lime and other minerals and useful rocks, including flagstones, grindstones, &c., and the tertiary limestone may yield a useful lime. Bog iron ore, and what is called in Scotland muir band pan,
are found in the gravel. They are of little interest, except as being identical with the same substances in Great Britain.
A few words on the general dip and strike of the strata may be useful. The metamorphic rocks are so bent, broken, and twisted, that it is difficult to give an opimon as to their prevailing dip, but the tilting action on the newer formations seems to me to have principally acted along a line from Cape Palisser to the northward, parallel to the East Coast. From this line, all the tertiary strata that I have observed dip gently to the westward, and on the other side of this line the supposed secondary rocks dip at a high angle to the eastward, and, if I am not mistaken, are north of Teawaiti broken through by this line of upheaval, and then dip both east and west.
Trusting that the above rough generalizations may serve as a guide, and lead to a more correct knowledge of the geological structure of the Province,
I have the honor to be,
SirYour most obedient servant,James C. Crawford.To His Honor I. E. Featherston,
Superintendent of the Province
of Wellington.
Wellington, November 30th, 1861.
Sir,—I have the honor to submit the foling theory for the discovery of gold in this Province, with the facts and reasoning on which it is founded; and which, whether of value or not, will, I hope, prove of interest.
A few days ago, I rode to the Karori and Waireka valleys near Cape Terawiti, and, although the men who had been at work at the diggings there were absent, and I was therefore unable to obtain various details, yet I found an inspection of the valleys, highly suggestive as to the direction in which a search for gold should be prosecuted.
There is nothing new in the mineral character of the rocks in the Terawiti district—they seem to consist of a slaty rock, laminated with veins of quartz; of the usual hard green crystalline sandstone, veined with thin threads of quartz; some hornstone or chert, indicating probably the no great distance of plutonic rocks; some serpentine; and a slaty rock containing iron pyrites, which may possibly belong to the first named stratum, but which seems to me identical with specimens of the bed rock of Tuapeka, which I have seen. All the above named rocks are repeated at various points of the Rimutaka and Tararua ranges, and therefore, if gold be found at one point, the inference is that it may be expected in others. The same rocks, or some of them, may be seen near the printers' flat in Makara, at various points on the Karori road, between Ngahauranga and Pitone, on the Rimutaka road, and elsewhere. One schistose rock which I have not previously observed, is exposed in the cutting of the new Makara road; it appears to be near the top of the series and looks a likely rock to search for fossils.
As a general rule, the lower the bed of rock and the nearer to the central fires, the more the rocks seem to be rendered crystalline, traversed by veins and possibly transfused with gold. It would seem as if the force of the plutonic rocks had been sufficient to act so far, but not to force themselves to the surface.
It is evident that the semi-metamorphic range, which here constitutes the main range of the Island, and which we must be content to call grauwacke, until the discovery of fossils shall enable us to assign to it a definite geological age, does contain some gold. Gold is found in it at Terawiti, in the Upper Hutt, and in various other quarters, and therefore, after all, it may be an auriferous range—discovery also may soon show that it answers Sir Roderick Murchison's description of gold constants, viz., silurian rocks, broken up by granites, porphyries or greenstones, inasmuch as I have found the eruptive rocks in the East Coast country, and I hope before long to find them in the main range itself; added to this we find serpentine in many parts of the range, and although few if any well defined quartz reefs or lodes are found, yet irregular veins of quartz, large and small, are very common. On the other hand, the quantities of gold yet found are small.
In considering the geological aspect of the district one inquires where is the most likely place to look for gold in quantity, and one naturally turns to the enormous development of “drift” gravel on both sides of the range, and in some of the valleys within it. After observation here and in the Middle Island, and duly considering the inadequacy of any other force to produce the effect, I am bound to suppose the existence of large glaciers, in every valley of our main range, during the glacial era, and at a time when the plains were submerged and the mountains stood as islands in the ocean. The moraines, the floating ice islands depositing their loads as they melted, have doubtless formed the mass of drift, which lies horizontally on the West Coast from Wainui to Rangitikei and beyond; and the sea has there spread the gravel regularly and evenly. The drift comes to the surface at Otaki and Rangitikei, and probably underlies the alluvium and the sand hills at the Manawatu, the lower part of the Rangitikei, and elsewhere. It will be found in small and irregular quantities in the different narrow valleys, including those of Waireka and the Karori stream, but denuded in places by the action of the streams. The Upper Hutt and Pakuratahi valleys have their deposits of drift, and probably in the Lower Hutt it will be found below the alluvium of the river; and in the Wairarapa this deposit is of immense extent and uncertain depth. It will be necessary to discriminate between the gravel of the drift and that which underlies the tertiary limestone; the former, in the Wairarapa, probably shows its Eastern limit where it rests on the grauwacke rocks, on Mr. Bidwell's run, while crossing the Ruamahanga the latter is seen resting on the tertiary shale. At the glacial epoch, when the gorges of the mountains were filled with ice, it is natural to suppose that the summits of the mountains were covered with snow, and I should therefere attribute the apparent alluvium of Karori, Porirua-road, and other table lands of the mountain range to a drift from melting snow.
There appears to be this difference between the drift of New Zealand and that of Europe, that in the former we have not yet found those large blocks of granite and other rocks, transported from their original locality for great distances, sometimes hundreds of miles, and of which the granite boulders used for building purposes in St. Petersburgh, and one of which forms the pedestal to the statue of Peter the Great, are good examples.
Considering therefore the enormous degradation and wearing away of rock, equal to the work of any number of quartz crushing machines, which is indicated by the drift of this district, it is evident that if the rocks acted upon contained any gold, that gold must be looked for at the bottom of the drift. From its specifing gravity it would be sure to find its way down until it found the bed rock to rest upon. For these reasons I would suggest that it is desirable that the drift should be bottomed in various places, to ascertain whether gold does or does not exist there;—this may be a serious undertaking and one requiring both capital and skill, for the chances are that the miners would have to contend with much water; but on the other hand, should the search prove successful, the results would probably be enormous and lasting, from the great extent of ground covered. What the depth of the drift may be, can be best proved by sinking a shaft; in some places, as at Rangitikei, it is evidently of great thickness; in others it may not exceed many feet.
Although I have been unable to get any details as to the quantity of gold found at Terawite, I have yet seen enough of the metal to show that it certainly exists in some quantity, and moreover, the specimens I have seen are of a heavier and more nuggety description than is usual in New Zealand diggings. The holes have been sunk in the drift, and I am given to understand, that in consequence of the quantity of water, the miners have never as yet been able to bottom their holes, and that consequently the ground has not had a fair trial. Whether it would not be wiser to sink through and bottom the drift in more open localities than the Waireka gully, is a question which I should like to hear answered by a practical miner.
I have lately expressed a doubt as to gold being found in any quantity in the grauwacke rocks of the Canterbury Province, which are identical with those of this range. An inspection of the Terawiti valleys, leads me to suspend my judgment on this point. In conclusion, I arrive at the following results:—
That gold in this Province is to be sought for at the bottom of the drift, where it rests on the older rocks.
That a search in the direction indicated offers a fair and reasonable prospect of success.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.To His Honor I. E. Featherston, Superintendent of the Province of Wellington.
P.S.—It is to be supposed that the drift extends northward into the Province of Hawke.
Wanganui, December 18, 1861.
Sir,—Although I have few additional facts to communicate concerning the discovery of gold in this Province, yet I find that I have some arguments still in store to show the small chance there is of finding what are called dry diggings in these parts, and that the existence or absence of gold will not be proved until the results of deep sinking shall have been tried.
In many countries, such as Great Britain or Australia, for instance, the mountains slope gradually into the valleys, the valleys into the plains, without any distinct line of demarcation; so that it is difficult to say where one begins and the other ends, while in New Zealand (excluding the country covered by tertiary rocks) the prevailing character is, that mountain and valley, or plain, meet abruptly, and therefore that the horizontal strata which form the plain may require as deep sinking to bottom through them near the hill as at a distance from it, the bed rock of the valleys appearing frequently to be a tolerably level surface of strata with their edges uppermost. The beds of drift or of alluvium, which may lie on the sides of the mountain above the level of the valley, are few and unimportant, and hence the absence of dry diggings.
The more I see of the rocks of our main range, the more I am satisfied that they answer Sir Roderick Murchison's definition of gold constants. The direct evidence is small, but the circumstantial is almost conclusive. It being granted throughout that the stratified rocks answer the necessary conditions with regard to age, then the circumstantial evidence rests on the facts that the rocks of the
range are dislocated, tilted, and upheaved at angles varying from 45° to vertical, and that they have evidently been altered to a great extent by the action of heat. There is strong presumptive evidence also that these effects have not been produced by comparatively modern lavas or traps, and therefore we may expect the true plutonic rocks to be close at hand, with almost as much confidence as if we found them on the surface—in addition to this, the rocks are every where traversed by diffused veins of quartz, and gold has been found in its detritus.
Having proved the gold constants by circumstantial evidence, it does not, therefore, follow that gold exists in payable quantities, or at all; but as I have already seen far more specimens of Wellington gold than I had seen of Australian in the year 1850, and which at that time led me to expect the discovery of the Bathurst diggings at no distant date, I have reasonably come to the conclusion that we have fair grounds for expecting to find the precious metal in payable quantities. Had no one attempted to dig in Australia it is probable that little more than specimens of gold would have been found there to this day, except perhaps the discovery of a few auriferous quartz reefs, which, wanting the skill and labour introduced by the diggings, would probably never have been worked.
It appears that gold has been found all along the West Coast—at all events at Terawiti, at Waikanae, and at Otaki; for that reason, and from the fact that New Zealand gold, like Australian, seems to prefer to lie to the westward, I should be inclined to recommend in preference a trial sinking on the West Coast, and particularly at Otaki, where the gravel seems to be more quartzose than the average; but otherwise, appearances are equally good in the Wairarapa; and the valleys and plains at Featherston, Greytown, or Masterton, look as “likely” for sinking as Waikanae, Otaki, or Rangitikei.
I find that the tendency of exploration is to go to the tops of the mountains to find the origin of the gold. Although this may result in the discovery of other minerals, and may be interesting to the geologist, it is not likely to be profitable to the gold miner.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.To His Honor I. E. Featherston,Superintendent of the Province ofWellington.
Whanganui, January 1, 1862.
Sir,—In accordance with your request that I should examine the rocks of the Whanganui river, and particularly the coal seams of the Tangarakau, having procured the services of Mr. Samuel Deighton, as interpreter, and an efficient crew of Maories, under the command of Topia Turoa, an influential chief, and son of Pehi, and accompanied by two volunteers, Dr. Tuke, whose services were at the command of the sick at our halting places on the river, and Mr. Walter Jowett, who had previously made the ascent, we started up the river on the 21st ult., and I have the honor to report as follows:—
In consequence of detention by Sundays, holidays, and rain, we did not reach Utapu, the residence of the owners of Tangarakau, about eighty miles from this township, until the morning of Saturday, the 28th, and there it was decided that the natives should discuss the question as to whether we should be allowed to proceed farther or not. We had previously remarked, from the commencement of our journey, that there was evidently some disinclination to allow us to proceed, but each tribe or chief seemed to wish to avoid the responsibility of stopping us.
The result of the “korero” was an announcement that Tangarakau was “tapu” to the Maori king, and therefore we could not be allowed to ascend it; but that as we had come so far, if we chose to wait until Monday, the 30th, we might then go up to the mouth of the Tangarakau, accompanied by one of the Utapu tribe, returning downwards on the following day. As it was impossible to proceed without both the consent and assistance of the natives, I was obliged to agree to that arrangement, and accordingly we encamped.
On the afternoon of the following day, Sunday, a rumour reached us that Pehi had sent up a letter, stating his wish that we should not proceed any further, on which I requested Mr. Deighton to ascertain if there was any change in the plans of the natives. After some conversation with them, they informed him that Pehi's letter was of no consequence, and that as they had promised we should be allowed to go to the mouth of the Tangarakau, we should still be permitted to continue our journey so far; but they had discovered that there was a “taiepa” or fence, meaning in our idiom a toll-bar, at Utapu, and that the charge for clearing the turnpike was thirty shillings.
It was represented to them that they had no right to stop a highway open to all; and that any discovery of minerals which might be made could only be for their benefit; that the navigation of the river was in their hands, and that they would see, more plainly than we could tell them, that nothing could be done without their co operation, but having made up their minds they seemed resolved to adhere to their determination.
Considering, therefore, that my objects could not be attained by merely ascending to the mouth of the Tangarakau, that I was tra-vellingtravelling in an official capacity, and therefore that any acknowledgment of a toll, on my part, would be adopted as a precedent, that having cleared one toll-bar there was no guarantee that we should not find many more as we proceeded, and that no profitable working of any minerals which might exist in that tract of country would be carried on, contrary to the wishes and without the help of the natives, I decided to turn the head of the cauoe down stream on the following morning, in case the natives should still continue obdurate; and as no change in their resolve appeared at that time, we returned towards the township, which we reached on the evening of the 31st ult.
Notwithstanding the present unsatisfactory termination to the expedition, I have strong hopes that the great natural intelligence of the natives will soon show them the desirability of encouraging rather than repressing the development of the wealth of their respective districts; and I have every reason to believe that, on the present occasion, the stoppage of our progress was against the wish of the majority; but, under the highly democratic system of the runanga, which seems here to resolve itself into a public meeting called by any body, which anybody seems in this case to have been a man of no importance, capricious decisions seem to be the natural result.
On the other hand, I have to state that we were received by the Maories with great kindness and hospitality, which, as a general rule, increased the farther we advanced from the settlement, and that their honesty is very remarkable, not an appearance of pilfering of any kind having occurred during the journey. The number of villages and of inhabitants up the river was far beyond what I had anticipated, and the movement and traffic in canoes form scenes both lively and unique.
In consequence of the abrupt termination of the journey, the geological results which I have obtained are few and unimportant. Previous to the ascent of the river I made out the following section on the sea shore, between the pilot station and Kai-iwi.
Tabular view o rocks at Whanganui in a descending series:—
Tertiary.
Sand (silicious and iron) in laminæ, sandhills at the top, exposing moa bones near the surface. I should suppose this stratum to be deposited by wind, could I thereby account for waterworn pebbles, mostly of igneous rock; lavas, tuffs, and traps, but also some of grauwacke and quartzite—thickness by estimation 50 to 60 feet.
Ancient forest, with many stumps erect, but most of the trees lying prostrate—5 feet.
A drift gravel of the same composition as in No. 1, say 20 feet thick, but irregular, and also containing fragments of tertiaries.
Soft yellow sandstone, say 60 to 70 feet.
Blue clay which appears to turn into a limestone near the sea level, marine fossils, ostrea, pecten, venus, trochus, terebratula.
N.B.—There is much pumice in some of the upper strata.
In ascending the river I was in hopes that we should find the strata tilted, and the lower beds cropping out, and that we should ascertain whether any secondary or palæozoic rocks lie beneath the tertiaries, and also perhaps discover the altered, or igneous rocks, on which I suppose the tertiaries, or other above named stratified rocks, to rest; but as far as we ascended we found the same series of teria ries, with slight variations, (as for instance, I was unable to trace the ancient forest, No.2, beyond a few miles from Whanganui), as at the settlement, preserving a remarkable horizontality, and consequently exposing nothing which lies beneath.
The surface of the country appears to rise in a succession of terraces, and were it not for the great denudation which has taken place, would probably have represented a series of rising plains; but numerous valleys of denudation have broken up the country into a very irregular surface. Valleys of dislocation have also assisted, of which probably the valley of the Whanganui itself is a grand example. A certain number of faults and slips affect very little the general horizontality of the strata, and consequently there are no valleys of undulation.
The distance of Utapu from the settlement is estimated at about eighty miles by the river, but from a bearing of Ruapehu which I obtained with a pocket compass from the hill above, viz., N. 70 deg. to 75 deg. E., I make the direct distance about thirty-four miles only. Near this I obtained ostrea in the lowest stratum, and at Parakino, twenty-three miles by river from this place, both ostrea and terebratula.
It would still be very desirable, with the consent of the natives, to obtain a survey of the coal seams at Tangarakau; even should it be found impracticable to work the coal so far inland, the dip and strike, nature and age of the seams, might be obtained; and an idea, formed in what direction they are to be looked for nearer to the sea coast, and should the dip prove to be in the direction of Whanganui, and appearances encourage the idea that the coal seams are persistent, and lie conformably (if I may be permitted to apply such a term to inferior strata) under the visible tertiaries, I would then recommend trial bores to be made at or near the township, which would clearly be the most convenient locality to work any seams which may lie beneath. There can be no doubt of the existence of coal at Tanga-rakau, for it has been seen by many persons, and the Rev. Mr. Taylor has shewn me a specimen which looks very good; but as I have seen so many mistakes made in judging of coal by the eye, I will not venture upon an opinion as to the quality from merely ocular inspection.
The Tangarakau is a tributary falling into the right bank of the Whanganui, and its sources must be near those of the Waitara.
I carefully examined the gravel of the Whanganui in hopes of obtaining some information from it. The river itself appears now to bring down no gravel from its sources, the wearing away of the stratified rocks forming sand; but the falling down and wearing away of the bed of the drift gravel (No. 3) has given a proportion of gravel to the bed of the river. This gravel I found composed principally of igneous rocks; traps, lavas, tuffs, and basalt, but with a certain proportion (say a tenth) of crystalline sandstone rocks, traversed by quartz veins, similar to the rock of the main range, and one boulder, and one only, of a slaty rock, with iron pyrites, which seems in New Zealand to indicate gold. These pebbles of altered rock must either have come from the Ruahine, which is improbable, or their original rock must form the bed rock here or hereabouts, and at the time of the deposition of this drift some part of it must have been subject to denudation. I feel convinced that the auriferous rocks, including granite, must cross the Strait from the other island, and lie underneath, but whether they will ever be found accessible, smothered as the country is by tertiaries, is another question. The grauwacke range of the east is found on both sides of the Strait, and the inference is strong that the old rocks of the western range should also be found on the North Island, although perhaps too far down to be discovered.
The report of indications of coal in the immediate neighbourhood of Whanganui can only, according to my present observation, be derived from some part of the ancient forest (No. 2.) The existence of any beds of tertiary or brown coal, beneath the blue clay, can only be proved by sinking or boring.
About two miles above Pipiriki, on the right bank of the river, we found a mineral spring, which, analyzed by Dr. Tuke, proves to be charged with sulphuretted hydrogen.
Linear bands of round stones, some of them like cannon balls, are seen in the river cliffs,—they appear in general to be concretionary sandstone, formed round some body as a nucleus. One which I broke seemed to contain a bivalve shell in the centre. The fish of the old red sandstone, in Morayshire, are frequently found in the heart of nodules.
A few remarks as to the country, although unconnected with my subject, may not come amiss. After fairly entering the hills from the settled districts, one finds the Whanganui river traversing a country of great sameness, but of extreme beauty. A dense and luxuriant vegetation of ferns, shrubs, and trees clothes the hills and cliffs; the valleys are warm and sheltered, and the country, although broken and hilly, can hardly be called mountainous. At a rough caculation the hills do not rise above the level of the river more than from 200 or 300 to 700 or 800 feet, and it appeared to me that were the country held in moderate sized farms, allowing combination of labour to open up narrow roads, it might support a comparatively dense population. Large holdings would be unworkable. The probability of being able to grow wine, or other valuable produce, is considerable. We found at Ohinemutu, a fine lemon tree with excellent ripe fruit, and maize is grown largely. No settlement of the district could be permitted, which did not leave ample room and verge for the natives, but there is an immense extent of country which can never be occupied by them. The general temperature which we experienced, was from 100 deg. to 120deg. Farenheit in the sun; and the winds which we heard of on our return to the settlement we had not experienced up the valley.
It is possible that the natives might be encouraged in other branches of cultivation, as already they begin to grow tobacco; they have introduced ploughs and harrows, and cows are milked daily at almost every settlement. No permanent improvement in the native villages can however be hoped for, while they retain the system of exhausting their land, and then removing to fresh ground; and consequently it would be highly desirable that an improved principle of agriculture should be adopted by them.
To set against the evidences of progress on the part of the Maori race, we found the natives at Karatea (Galatea) cutting down a beautiful grove of karaka trees, to catch, roast, and eat the lizards which are found in their hollows, as they had found that the lizard is the root of all evil!
With regard to the river, its course lies too much to the westward to form the main line of communication with the interior; and I fear that little can be done to improve its upper navigation. Money no doubt could lock it to its source; but whether any locks could withstand the force of floods or chance of earthquakes, is immaterial, for it would hardly pay. Its navigation must therefore remain in the hands of the Maories, or of men specially trained for the purpose. It may be described as a succession of rapids and long deep reaches, and winds greatly. The flood mark at Pipiriki was about 25 feet above the bed of the river. As the mass of the valleys are valleys of denudation, apparently following the present lines of drainage, it is just possible that a good line for a road into the interior may be found equidistant from and between any two of the rivers running from thence, where an undenuded backbone may have been left.
The difficult part of a road required to connect the open and central plains of Taupo with Whanganui, does not probably exceed thirty miles in a straight line.
I have to thank Mr. Richard Booth of Pipiriki for his assistance and attention to the expedition, and Mr. Samuel Deighton for his skilful management of our transactions with the Maories.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.To His Honor I. E. Featherston,Superintendent of the Province ofWellington,
Whanganui, February 17, 1862.
Sir,—On the 8th of January last I left this place for Rangitikei, accompanied by Mr. Samuel Deighton as interpreter, for the purpose of exploring the country along the course and towards the sources of the Rangitikei river; and as I have now traversed the country from here to Rangitikei, thence by the ascent of that river to the Patea country, thence across the open country to Taupo, and thus, heading the Whanganui river, descended upon its right bank, and from thence passed down stream to the point from whence I started, the journey, although tedious, enables me to dispose geologically of a large extent of country.
It will be seen in this report that I have had to modify several statements which I had previously made; but as geology is essentially a science of observation, one must always be prepared to admit fresh evidence, and to alter one's views accordingly.
Having arranged for a canoe to take us up the river, and after a slight detention on account of rain, we started from Mr. Swainson's on January 14th, and six days constant poling brought us through the forest into the Patea country; this was very tedious compared with a land journey, but it enabled me to follow the sections of the strata during the whole distance, and therefore to speak confidently of their character—I find the strata of the Rangitikei to be essentially the same as those of the Whanganui river. Leaving out the “drift” and ancient forest, or throwing them in with the upper sandstone, I would, for simplification, classify the Whanganui series in three strata of tertiary rocks. Taken in a descending series, they would be as follows:—
Upper sandstone.
Blue clay.
Coal shales.
I think I may safely venture to give the latter name. If we give an average thickness of 200 feet to each of these strata, we shall have a total average thickness of 600 feet of tertiary rocks. It was impossible, without devoting more time to the investigation than was at present advisable, to make a correct measurement of the thickness of the tertiary strata.
In the ascent of the Rangitikei river, the drift, which is largely developed in the settled district, becomes comparatively unimportant, but may generally be seen capping the cliffs; and as it rests throughout on the tertiary rocks, I cannot recommend a search for gold in it; still less can I recommend sinking through a great thickness of sedimentarytertiary rocks on the chance of finding gold beneath; but bearing in mind that the “drift” of the Whanganui district is derived partly, and that of the Rangitikei, and from thence to the southward, principally from the abrasion of silicious slate and crystalline sandstone rocks, there is always a possibility of finding some gold in it. As the drift gravel is accessible in numerous sections of cliffs, this point can easily be settled by driving into them without going to the expense of sinking, by any one curious in the matter; but failing the discovery of gold in this upper drift, no gold can be expected before sinking through the whole thickness of the tertiaries, either sedimentary or volcanic, except possibly near the sources of the rivers.
I think my estimate of 600 feet may in the meantime do for all practical purposes, but the upper sandstone must sometimes alone measure at least 400 or 500 feet. Continuing the ascent of the Rangitikei, the blue clay forms the cliffs for a considerable distance, and higher up is succeeded by a soft rock, striped with frequentbands of sandstone a fewinches thick. This I suppose to be the representative of the coal shales of the Whanganui, although it somewhat differs in mineralogical character. Its characteristic fossil seemed to be “pecten.”
The dip of the rocks in the Rangitikei is generally greater than in the Whanganui and to the south west, from the Ruahine in the direction of Whanganui; but the rise in the bed of the river is rapid and continuous, and consequently the changes of strata intersected are few. The character of the Rangitikei and its adjoining country is similar to that of the Whanganui; but the river is very inferior for navigation and the district is not equal in beauty of scenery, although in the latter point it is in some respects unique. The deep narrow chasms, through which the river flows in its upper part are singularly beautiful, and the tributary Moawhanga, which we ascended on the 20th presents a cleft, perhaps 150 feet deep and only 18 feet wide, with perpendicular sides, and the trees meeting in an arched overhead, the beauty of which, clothed with ferns and other luxuriant indigenous vegetation, with the rays of light glancing down wards through the trees, can be easily understood. The principal tributaries of the Rangitikei fall into its right bank. The Hautapu and Moawhanga are the largest.
On the 20th we left the canoe, and ascended the cliffs on the banks of the Moawhanga, to Pawerawera, where we found no one at home. On the 21st we proceeded to Popotahi, and here we found very few inhabitants; only two men and some women and children. I had wished to have got fairly into the gorge of the Rangitikei in the Ruahine Range, which appeared to be about fifteen miles distant, where I expected to find the base of the tertiary rocks and ascertain on what they rested, but after some consultation here I found that I was neither supplied for the trip, nor, in consequence of the absence of the inhabitants, could I get the assistance necessary. The actual gorge of the Rangitikei is apparently in a very difficult country, the tertiary rocks, covered with dense forest and no doubt intersected by the chasms which I have described, lying high up on the flanks of the older rocks; and an exploring party ought to go well supplied, making up their minds to work gradually on, if only a few miles a day. Above the junction of the Moawhanga with the Rangitikei, two days poling up the main stream, lies the pa Te Awarua, and from this point the gorge in the mountains would probably be easiest explored. It is likely, however, that the information required might be obtained with little difficulty on the road from Patea to Napier, and had I been able to obtain horses at Patea I should have ridden a day's journey in that direction. It would be desirable to ascertain if the coal seams of the Whanganui extend to the Rangitikei, and this might be found out in the gorges of the mountains. I observed a small seam of semi-lignite at one point on the river, but it seemed to be local and of no importance, and belonged to the upper sandstone. It was a great relief to emerge from the deep clefts and dense forest of the Rangitikei on to the open country at Patea. Ascending a hill near Popotahi I could trace the ter-tiary rocks lying high on the flanks of Ruahine to a height of I should think not less than 2000 feet above the sea; also extending to the North and in direction of Napier, as far as the eye can reach. Some of the hills in the latter direction are capped with a scarped stratum, which I take to be the limestone of Ahuriri.
The question arises, how far do those tertiaries extend to the Southward? and I strongly suspect that they reach the Manawatu, if they do not extend still further.
Having with some difficulty procured a guide, and an old horse to carry our baggage, we proceeded towards Taupo on the 22nd of January, only reaching Pakehiwi on the first day, where we had to stop to change our guide. Our route lay through an open and well grassed country, but also presented a large amount of forest within sight. We crossed the Moawhanga by a bridge over the chasm, and here I found “venus” of a small kind. On the 2rd we passed through a similar but perhaps better country. At Turangerere, on the Hautapu, there is a beautiful waterfall, and here I again found “venus.” In fact, beds of these shells were found until within perhaps ten miles from the base of Ruapehu, when igneous products took possession of the surface. Turangarere was the principal residence of the late worthy chief Te Herekiekie.
We encamped on the 23rd at a place called Poutamurengi, on the banks of the Hautapu. This stream is a tributary of the Rangitikei, tokes its rise in the Ruahine, runs at first considerably to the Westward, but turning about this point falls into the right bank of the Rangitikei in the middle of the forest.
Our ascent from Patea, although not very perceptible to the eye, was evident enough from the change in the vegetation, and on the 24th we found ourselves traversing the bare and blasted volcanic country at the foot of Ruapeha and ascending the stinking bed of the Wangaehu. Here was pointed out the course of the avalanche which had destroyed the Wangaehu bridge. It proceeded from the top of Ruapehu, rushed down through a winding chasm or watercourse on the East side of that mountain, from thence in a broad stream across the plain, or rather inclined plane at the base; clearing off large patches of bushes and other vegetation, and so broadside into the Wangaehu, which here skirts the mountain; thence down that river to the sea; and, let me here observe, that as all the rivers from the Rangitikei to the Whanganui, both inclusive, flow in chasms, which may be blocked up at any time by an avalanche, by an earthquake threwing down the cliff, which actually happened in the Rangitikei in the year 1855, or by other causes, an accumulation of water may be collected which, when it bursts, would be dangerous to any bridge not constructed with a clear waterway.
It does not follow that the valleys of dislocation, or cracks, through which the rivers flow, have been been caused by plutonic action; probably they may have been, but shrinking of the mass is quite as likely a cause. The tertiary strata are very little disturbed except by local slips.
We next observed the stone on one side of which the Waikato rises clear and bright and flows to the North, while on the other side the Wangaehu with bitter, sulphureous, and nauseous water takes its course to the South. We had not proceeded far, however, before I observed that the Waikato received several affluents of as apparently nasty water as that of the Wangaehu. This is the highest point of the road, and as we gradually descended the vegetation improved, although all along the bases of the Ruapehu and Tongariro the plants are alpine in character. Kahikatea and black birch, full grown, but only a few feet in height are common. The mountain torrents are frequent and often very beautiful, but their height and rapidity during winter, and the depth of snow which is said to lie on these plains, must prove a great obstacle to a permanent road over the high country, which shall be open all the year. On the 24th we encamped on the banks of one of these torrents, called Waihohonu, and I think the prettiest of them all.
On the 25th we passed Roto Aira, and here was the first village we had come to since leaving Turangerere on the Hautapu, at which place we found no one resident. Compared with the population on the Whanganui the country we had passed through is comparatively uninhabited. On the Rangitikei, from the settled districts to Patea, we found only a few families. At Roto Aira the Maories were very civil, and they procured us horses to ride to Tokanu, at the south end of Lake Taupo, where we arrived in the evening. The block of volcanic mountains which we had just passed is of magnificent proportions, and if easily accessible would attract many visitors. Ruapehu is doubtless the most ancient, and is the most elevated land in the North Island, attaining a height of upwards of 9000 feet, forming as it were the chief gem of the volcanic range, placed in a setting of tertiary rocks. Probably its forces have long been extinct. It appears to me to be composed of the harder volcanic products, compact lavas, traps, &c., and puts me in mind of Tapuanuka, the inland Kaikora, in its shape and the apparent character of its products; although it is altogether a much handsomer mountain, with a more lengthened and graceful sweep at its base. Tongariro lies to the north of Ruapehu, and is a mountain of great site but very inferior elevation. It has every appearance of being a broken down crater. No visible signs of volcanic action now appear from the interior of this crater, but the grand active cone is Auruhoe, which is situated on the southern glacis or slope of Tongariro, and is therefore a lateral cone of that mountain. It is a regular cone of a very beautiful shape, and reaches a height above the sea of upwards of 6000 feet. According to the natives its last eruption occurred about twenty-five years ago, when it threw out large quantities of stones; its top fell in, and they say spoilt its appearance. It always sends forth volumes of smoke, and is said frequently to emit ashes, which disagreeably affect the eyes, and to give forth rumbling sounds and discharges as of cannon. It is a remarkable fact, however, that very few natives live in sight of the mountain, and at the same time sufficiently near to be able to give a good account of it. From the village at Roto Aira the cone of Auruhoe is invisible; and the natives at the south end of Lake Taupo are shut out from a view of the mountain by intervening hills; while those at the north end are too remote to observe phenomena correctly,—consequently a great deal may happen which is not observed. On the north west flank of Tongariro, outside the crater, there is a large puia, or hot springs said to be a specific for certain diseases, and which also emits large volumes of smoke and steam.
At Tokanu there is a very large area of hot springs, both in the delta of the rivers, which there flow into the lake, and on the surrounding hills, more particularly where the late chief Te Heu Heu was smothered; and as this was my farthest point I shall omit all mention of the geysers and hot springs, lakes and rivers, to the north eastward of Lake Taupo, which I know of only by hearsay. At Tokanu I found pebbles of grauwacke and quartz, in the middle of the hot springs. There was nothing to show whether they were an old deposit, or had been brought down the rivers from the Kaimanawa and deposited in the delta, which here runs far into Lake Taupo
I have said above that we carried the tertiary rocks to within about ten miles from the base of Ruapehu. When well abreast of that mountain, I observed a range rising parallel to it to the eastward, and forming the other boundary of the valley of the Waikato rivers which is called the Tongariro before it enters Lake Taupo. This range is called Kaimanawa,—is a powerful range, rising to a great elevation, and appears to run about N.N.E. in the direction of the Bay of Plenty; it is not a continuation of Ruahine, but is in a parallel line to it, and is evidently composed of slaty or grauwacke rocks. I was anxious to examine this range, and was promised horses by the natives for that purpose; but whether they could not really find the horses, or whether they were averse to my visiting the range and would not find them, I do not know; but as I did not care to ford the rivers on foot, I was obliged to leave Taupo without effecting this object. Very little of the range, however, lies in the Province of Wellington; it is principally in the Province of Auckland, although perhaps most accessible, at the southern end, from Napier.
At Tokanu we were detained for a week, partly trying to get the above-mentioned horses, but principally by constant thunder storms and rain. What with the damp and warmth of the atmosphere, and the heat of the hot springs, we found the climate to be most relaxing and debilitating. I was informed by the Rev. Mr. Grace at Pukawa, that pumice stone is excellent for building purposes, being watertight, and an excellent non-conductor. This may be worth knowing in those parts of the Island where other building materials are scarce and pumice is plentiful.
On the 3rd February we left Lake Taupo, proceeding over an open pumice stone country, with very fair grass, on which we observed some of the sheep owned by the Maories, until we were obliged to halt, by a sudden and heavy thunderstorm, at the entrance of the bush, where the path leaves the Rua Mata plains. On the 5th we had a very hard day's walk through the bush, and over a very steep road to the banks of the Whanganui river, which we found we had headed, and consequently struck on the right bank at a place called Terena. During this day we crossed a tributary of the Whanganui called the Waipare. Here I found “in situ” what I suppose to be the base rock of this part of the Island. It is a silicious slate with quartz veins. We waded the Whanganui several times and its tributary the Whakapapa with some difficulty, holding on by poles. The rivers were rapid and cold and the stones very slippery. On the 6th we reached Tapuia Kumera, where we found Topini te Mamako, the principal chief of this part of the river, from whom we received every facility. He informed me that two days' journey up the Whakapapa, which falls into the left bank of the Whanganui, that river runs through slate rocks, with crystals of some metal in them, probably either manganese or iron pyrites. This tends to corroborate my discovery in the valley of the Waipare and goes far to show that a floor or base of slate or other old rock, most likely tilted and folded, lies immediately beneath the tertiary rocks. At the Waipare I could not find a geological section, but it appeared to me that sedimentary tertiary rocks were above the slate, coverd again by pumice and perhaps tufa. I also found here a conglomerate of small pebbles, but not in a position to enable me to draw any conclusions.
The first sedimentary rocks which I observed in the Whanganui I have ventured to call coal shales. They are true fissile shales, striped by bands of a grey sandstone a few inches thick. A little below the Otunui they are seen to pass under the limestone at the base of the blue clay, but they appear again further down, and their upper surface must be near the river level for a long distance. I was unable to discover any fossils in the coal shales, but from the nervous anxiety of the Natives, who supposed every stone I picked up to contain gold, I was obliged to be very chary in my search, to avoid exciting their suspicions. That rock of the Rangitikei, however, which I take to be the representative of the coal shales of Whanganui, yielded a pecten which I suppose to be an undoubted tertiary fossil.
A little above the upper Paparoa rapids I found, among other fossils, a large cucullœa, which I am inclined to think will, on comparison, connect the blue clay of this coast with that of the East Coast and the Upoko Ngaruru, where the fossil cetacean was discovered.
The Upper part of the Whanganui has large deposits of pumice and volcanic ashes, passing into tufa, which sometimes cover the surface to a considerable depth.
I am not prepared to state the relative age of the volcanic and sedimentary tertiary rocks. The deposition of the coal supposes land above the sea at the time, with possibly several elevations and depressions. The eruptions of Ruapehu may have been going on during this period, and while the depression went on during which the higher tertiaries were deposited. The sedimentary tertiary rocks seem to keep at a respctful distance from the volcanic chain, as if the action of heat had prevented organic life within its range. The sedimentary rocks were not observed to be in any place covered by volcanic products, except by pumice, volcanic ashes, and rolled pebbles; all of which might have been carried by water, nor were the sedimentary tertiaries observed to rest upon volcanic rocks. The later volcanic eruptions seem to have thrown out principally pumice and ashes, and to an enormous extent.
The depression must have continued with perhaps some alternations until the deposition of the highest of the tertiaries, when the country must have gradually risen in its present form, the eruptions from some part of the volcanic chain continuing; and the sedimentary tertiary rocks, which would otherwise have presented an even surface, exposed to enormous denudation, in the present lines of drainage, which has in many places left only sharp ridges behind.
As the deposition of one rock presupposes a corresponding wearing away of another, it is difficult to suppose that the great mass of tertiaries have been formed by the wearing away of the hard slate rocks, assisted perhaps by volcanic ashes and other products, and one would naturally look for the remains of some softer secondary rocks which had supplied the material, but such have not yet been found in this part of the country.
As Topini was finishing his harvest, we found it impossible to press him for a canoe, and were consequently detained for four days at Tapuia Kumera. On the 11th we started from that place, and on the following morning reached Marai Kowhai; at the junction of the Ohura with the right bank of the Whanganui, and where the former river forms a splendid waterfall. Here, a short distance up, is a seam of coal, which unfortunately I did not see, but from which I hope to obtain some coal for inspection. As I had carefully noted the strata, my not having seen the seam is of little present consequence.
Both in the Rangitikei and the Whanganui I have observed transported boulders of igneous rocks, many tons in weight, so that I must modify a statement which I have formerly made concerning them.
At Marai Kowhai we had heavy rain, so that when we started on the morning of the 12th, there was a heavy fresh in the river and many of the rapids were obliterated. Our rate of speed was great, we reached Pipiriki the same evening, carrying the bottom of the blue clay, or the top of the coal shales, about flush with the river past Tangarakau, near which point we met the man who had stopped us on our previous excursion poling up a rapid as we glided rapidly past him to Pipiriki. To give an idea of the scenery of the Whanganni I may state that I counted no less than one hundred and eight waterfalls which we passed in one hour, and that a corresponding number might be counted for two days' journey down stream; of course some of them are not permanent.
At Pipiriki we met the Rev. R. Taylor, who gives the estimate of Ropata Kora (a chief of Utapu) of the thickness of the Tangarakau coal seam at eight feet, and his own estimate of the Ohura coal seem at three feet.
After seeing the river in a fresh my views as to its navigation are considerably altered. I think it possible that steamers constructed for the purpose might navigate the river during the time that it is sufficiently high, which may be for several months in winter, and whenever there is sufficient rain in summer. The vessel would require to have considerable strength to stand bumps, and great power to put on at the rapids. The worst rapids might be cleared out a little and straightened; the numerous eel weirs would perhaps be found a considerable obstruction. The two worst rapids are Ngaporo and Paparoa—the former below the junction of the Maunga Nui te Au; the latter about half-way between the Ngarue and the Ohura.
I should consider the navigation of the river, however, with reference to the opening out of the country rather than as confined only to the working of the coal. Supposing a navigation to be in prospect, there are three points on the river of great importance.
The highest is Taumarunui, two or three miles below Tapuia Kumera, and at the junction af the Ngarue with the Whanganui on the right bank of the latter.
The Ngarue, shortly before, receives the waters of Te Ringa Motu, and from this point an open country is said to extend with only one intervening bush to Ngaruawahia; thus giving communication with the Waikato country, and from here it is likely that a good road can be got to Taupo.
The next point is Marai Kowhai, and the line of the Ohura. This river leads through a fine counry to the Waipa and the Maniopoto country; and here a coal seam crops out.
The next point is the line of the Tangarakau, which leads to Waitara, and two days' journey up this stream coal again crops out. Estimating our rate of speed down stream at six miles an hour, I make the distance of the Ngarue from the township 170 miles;—of Marai Kowhai and the Ohura river, 115 miles;—of Tangarakau river, 86 miles.
I did not think it advisable at this time again to broach the subject of the ascent of the Tangarakau, as it would certainly have ended in a refusal.
With regard to working the coal, supposing it to be shipped at Marai Kowhai, where it could be loaded in the Whanganui river itself, I look upon boats or barges as out of the question; at all events, if constructed of wood, they would soon be knocked to pieces in the rapids, A large canoe might carry two tons,—heavily laden she would probably require and would take on an average four days to descend the river to the settlement, and would require a crew of four men. The return voyage has also to be considered, of not less than eight days, so that no very great result can be anticipated supposing all the canoes, and Maories on the river, to be employed on the traffic. I would therefore strongly recommend a trial bore to be made, near the settlement, to ascertain if the coal strata lie beneath,—choosing a place for sinking as near as possible to the base of the blue clay, but taking care to avoid the actual valley of the river, in which dislocation might have extended through the coal. I would ad-viseadvise the bore to be driven through the whole thickness of the coal shales, to find if there is more than one seam. Should it be wished, however, to prove the coal seam at Tangarakau, it might probably be easily sunk through on the banks of the Whanganui itself. In this case the water carriage would be about eighty-six miles only, and the upper Paparoa rapids would be avoided.
I have stated that no gravel is now brought down from the heads of the Whanganui, but I now find that any amount may be. The river rises in Tongariro, as does its affluent, the Whakapapa; and the commencement of its course is through the volcanic zone. It runs at first in a direction to the northward of west. The Ngarue, which receives the waters of Teringamotu, is at the junction nearly half the size of the Whanganui. Teringamotu rises at the back of Lake Taupo.
I would again call your attention to the immense belt of forest country, thirty or forty miles broad, which extends from the flanks of Ruahine, sweeping round between the settled districts and the open country of Patea, to the Whanganui river, and so on to the westward into the Province of Taranaki. This country is full of rich and sheltered valleys, and is capable of supporting a large population, and of producing most valuable commodities; it is, except on the banks of the Whanganui river, almost without population, and even there it may be said to be in a state of nature. This country is very much broken, but for that reason it enjoys a remarkably warm and sheltered climate, suited, I should think, to the culture of the south of Europe. The lemon-tree of Ohinemutu speaks volumes. I look upon this district as peculiarly suited to the patient industry of German settlers, working in village communities, and giving mutual assistance in road-making and other things, as it is only by steady, unintermitting, and combined labour, that it can be reclaimed. It will be a pity to see this land left unoccupied, and the German settler would understand the culture required.
Of course, as the country rises in height the climate may be expected to be less genial, but up to the head of the Whanganui river we found maize, tobacco, and water-melons thriving.
Not one only, but several roads, should also be opened through the belt of bush, if for nothing else than to allow the driving of stock to Auckland. One line might be improved on the present road from Rangitikei to Patea, and it is said that a very small outlay would open a good road to the Taupo plains, starting from Upoko Ngaro, on the Whanganui, and taking a line between the Maungawhero and the Wangaehu. It would be desirable, if Possible, to avoid the highest part of the plateau below Ruapehu, as the road there could hardly be kept open in winter, from the quantity of snow and the swelling of the streams. The continuation of the eastern road, by the line of Rangitikei to Patea, might possibly intersect the Hawke's Bay road without getting to a great elevation.
The result of this journey may be stated as follows,—
That a broad belt of sedimentary tertiary rocks extends from the flanks of Ruahine, passing under the sea on the coast side, and circling round the volcanic chain in the interior, sweeps round to the Whanganui river, and from thence doubtless to the Western boundary of the Province of Wellington, and indefinitely beyond.
That apart from minor seams these tertiaries may be grouped into three strata, taken at a rough average thickness of 200 feet each, making an average thickness of 600 feet of tertiaries, at any point where all the strata are present.
The above is subject of course to any corrections, that an examination of the intervening country may render necessary.
That taking the height of the upper part of the Whanganu river, (say at the Ngarue), above the sea, ati the same height as Lake Taupo, or 1300 feet, (Hochstetter's estimate); and allowing 300 feet for lift of strata above the line of the river bed, observed between the settlement and the above-named point, and taking the direct distance at seventy miles, the dip of the tertiary strata will be represented by an angle subtended by a perpendicular of 1600 feet, with a base line of seventy miles.
That there is reason to suppose that the tertiary rocks rest unconformably on a base of slate, or other old rocks whose age has not yet been determined, and that these rocks may be found cropping out towards the sources of the rivers, where the volcanic and sedimentary tertiary rocks approach each other, and also in the Ruahine and Kaimanawa ranges.
That in these older rocks only, or in the drift derived from them, is there a chance of finding metals, but that no actual metallic indications have been discovered.
That the cool seam of the Ohura is probably a tertiary coal, and that it may be expected to underlie this settlement.
That the coal seam of Tangarakau is probably of the same age as that of Ohura; out not having been nearer than two days' journey from the outcrop, this point must remain for future investigation. I have, however, a report from Mr. Soulby of this place, who has tried the coal, and reports that it is very inflammable and probably full of gas, but does not yield a strong heat. He will endeavour to get the natives to send down a sufficient sample for inspection and analysis. He also states that it is got in large blocks.
As soon as the native mind is sufficiently tranquil it would be desirable to open up both the seams of the Tangaraukau and of the
Ohura sufficiently to prove them. I have reason to suppose that the tertiary rocks extend at least as far south as the Manawatu, and it is now my object to ascertain that point, and to observe the geology of the gorge of that river, and then to take the Otaki river on my way to Wellington. It is reported to me that there are slate rocks in the bed of the Turakina. This I propose to inquire into, while on my way south. It is quite possible, but I hardly think probable, that they there crop out.
I have a suspicion that we have two drift formations, of different ages, as has I believe been found in Victoria, but am not yet in a position to prove it.
During the journey we found the natives civil and hospitable, without exception.
I have the honor to be,Sir,Your most obedient servant,James C. Crawford.His Honor I. E. Featherston,
Superintendent of the Province
of Wellington
Wellington, March 17, 1862.
Sir,—Although unconnected with the subject of minerals, an exploration of the Manawatu leads me to lay before you some remarks concerning the eventual settlement of that district, with a view to a thorough development of its resources.
I have long been impressed with the fact that the agricultural resouurces of New Zealand with not be appreciated until irrigation is understood and practised. With a comparatively warm climate, and an ample supply of water, the results of irrigation may be expected to be astonishing. I have already expressed an opinion that the broken forest country lying between the Rangitikei and the Whanganui rivers inclusive, can only be successfully worked in small or moderate holdings. I would now further remark that these rivers lie deep below the surrounding country; and, except perhaps near the mouth of the Rangitikei, are not adapted for irrigation.
The Manawatu, on the other hand, has quite a different character. It flows through comparatively low banks, and during floods, covers a large extent of the low country; while at the gorge, and for a considerable distance below it, there is evident to the eye a head of water, which could easily be directed to any lower point re-required.
From the sea to a considerable distance inland, say ten miles, the surface is covered by sand hills and sandy flats, which not only are very poor in their present state, but are a source of danger when broken into, to the neighbouring good land, as the sand blows and travels at a considerable rate.
This land by means of irrigation could be converted into fertile meadows; not only making a handsome return, but removing the previous danger of an irruption of sand.
On a moderate estimate there must be one hundred square miles of the above-named de-description between the Manawatu and the Rangitikei rivers; all of which, supposing the supply of water sufficient, might be brought into great fertility.
Between the Manawatu river and Wainui there is, perhaps, a larger extent of similar country, which would be immensely improved by irrigation, as far as the supply of water and the nature of the levels will permit. As the smaller rivers on this coast are useless for navigation, they might be employed, without compunction, on irrigation.
In connection with this subject the navigation of the Manawatu has to be considered; and I think the river might be made to serve both purposes. The navigation, except for canoes and rafting timber, is difficult and of little consequence, above Puketotara; and as all the water proposed to be abstracted for irrigation ought to be returned to the river, less by what is absorbed by extra evaporation, the scour at the mouth might not be much diminished, and the sediment which now goes to form sand banks at the bar, would to a great extent be spread over and fertilize the soil.
In the Manawatu district there are also swamps of very large area, which are probably beyond the power of private means to drain; so that, I would suggest, a great part of the district requires to be put in order, before it is settled. A combined system of drainage and irrigation, is what is required.
An irrigation canal, taken away from near the gorge, would relieve the present flooded lands.
It is evident that a large capital would require to be invested in the improvements which I propose, and that a great many details would have to be considered, such as the size of farms, whether the holders of the irrigation canal should have the land in freehold, or merely supply the water, &c.; but I do not here propose to enter into any details, as I consider it sufficient for the present, to put forward my views, so as to elicit discussion.
A consideration of the subject of irrigation may be deemed premature, as it may be considered that neither the present population of the Province, nor its state of advancement, would warrant the expenditure required; should this view be generally adopted, I would then advise that that the levels for irrigation canals should be taken, and that the necessary reserves should be made for their ultimate construction, with also a power to be retained to make use of the waters of the river when required.
It may, however, be remarked that irrigation is practised successfully in so young a colony as Van Diemen's Land, and also in the Republic of Chilli, where the population is scanty.
Irrigation farms would require a more skilful husbandry than is usually practised in this Colony; but as there is no lack of intelligence among our farmers that difficulty might soon be got over.
The Manawatu is also evidently meant for the centre of a great timber trade, as the river is well adapted for floating timber down, both from the forests on the Western side of the range and from the seventy-mile bush on the East side—and, in the forest country at least, the lumberer should precede the settler.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.His Honor I. E. Featherston,
Superintendent of the Province ofWellington.
Wellington, March 17, 1862.
Sir,—I have the honor to report that I left Whanganui on the 24th February, for the purpose of exploring the country in the basin of the Manawatu river. On my way I examined the bed of the Turakina river for some slate rocks which were there said to crop out. These supposed slate rocks I found to consist of some horizontal bands of soft tertiary sandstone; and the general appearance of the rocks, looking up the river, being similar to that of the Whanganui and Rangitikei rivers, gave me no encouragement to proceed farther in their investigation, without having more time at my disposal than I then had.
On arriving at the Manawatu I received every assistance from Captain Robinson, in furthering the objects of the expedition; and on the 28th we proceeded to Puketotara by land, from whence we proposed to ascend the river by canoe.
At Puketotara there is a large native settlement. The teacher there, Hoani Mehona, or John Mason, entertained us in an excellent weatherboard house, and the church is finished, and in good repair.
In consequence of the disinclination of the Maories to be absent from their homes on Sunday, we were detained at Puketotara until Monday the 3rd of March; and as that day was very stormy, we were still further delayed until the following day—bad weather set in, there was a heavy fresh in the river, and our progress was tedious in the extreme.
It was therefore the 8th of the month before we reached a camping place on the west side of the gorge, just above the junction of the Puhangina river with the right bank of the main stream; and at this point, swarming with mosquitoes and sandflies, we were, in accordance with native custom, obliged to remain all Sunday.
On the lower part of the river I had observed what appeared very like the blue clay, showing itself a few feet above the water (particularly on the right bank, about a mile below Puketotara), but at and near the gorge it became unmistakable, appearing in cliffs thirty or forty feet high, capped again by drift gravel averaging abont twenty feet in thickness. At the same time it must be observed that the exposed part of the blue clay was unfossiliferous, the characteristic fossils being doubtless below the river level. Opposite the camping ground I obtained venus and pholadomya, but I am not sure whether they belong to the lower part of the upper sandstone, or to the upper part of the blue clay. These fossils were so soft as to render their removal difficult. At this point, opposite the camping ground, the strata dip to the westward at an angle of 20 deg. to 25 deg.; but I am not satisfied whether this is the true general dip along the side of the grauwacke range, or only a local slip. The general dip over this district is either imperceptible, or slightly to the west.
On the 10th we passed through Te Apiti, or the gorge, which we entered immediately on leaving our camping ground; this pass is entirely through the usual grauwacke rocks, and is certainly a most remarkable feature, inasmuch as one of the principal rivers of the island is enabled by it to traverse the main range, and discharge its waters into the sea on the opposite side of the island from whence they take their rise.
It took us just one hour in the descent of this gorge, and therefore its length cannot exceed six or seven miles, including the windings of the stream. The height of the range above the stream being 700 or 800 feet. With so short a distance and so moderate a height to surmount, there can be no great difficulty in the construction of a road to connect the level land on both sides of the island. The the dip of the stratification of the grauwacke rocks is either highly inclined, or vertical, and their composition is similar to that of the rocks near Wellington.
Passing through the gorge to the 70 mile Bush, we emerged suddenly upon a level forest country, where I immediately again recognised the tertiary rocks resting on the flanks of the grauwacke. Here I found the blue clay and the small “venus” which I had left on the other side of the gorge, and in addition found some of the comminuted shell limestone of Ahuriri.
We proceeded onwards for some miles, when I saw that in a continuation of the journey we should only be travelling over the tops of the tertiaries, and therefore determined to return, and we accordingly turned the head of the canoe down stream, and reached our old camping ground at Puhangina on the same evening.
On the 11th we reached Puketotara, and on the follwingo day arrived at the township at Te Awahou.
The result of this exploration is to show that the tertiary rocks skirt the Ruahine ranges from the Rangitikei as far as the Manawatu, and point further south in the direction of Otaki. It will be of interest to ascertain if they underlie Otaki; and if they go still farther south and pass through the channel between Kapiti and the front ranges of Tararua.
These rocks lie lower at the Manawatu than in the upper part of the Rangitikei, and only show a small portion of the blue clay above the river level. The upper sandstone is only found in fragmentary patches.
The drift is insignificant in thickness compared with what I supposed it to be. It generally averages however, where present, twenty or thirty feet through.
In none of the drift in any district have I found any boulders of foreign derivation, or that have not been derived from the nearest mountains. The tertiary rocks of the western rivers all point towards Cape Farewell, and there is therefore every appearance of a great tertiary basin, of which the eastern and northern rim lies on the flanks of Tararua and Ruahine, curves from thence round the volcanic zone, and thence to the west coast at some point to me unknown. That the southern rim of this basin will be found in Massacre Bay there is strong reason to suppose, and therefore a comparison of the fossils is desirable. I think it will also soon be shown that the great tertiary basin is in connection with a great tertiary field extending over a great portion of the north, and a large part of the Middle Island.
I feel some disappointment in not having found any coal seams to the eastward of the Whanganui river. At the Manawatu one could not expect them, as the strata are too much drowned; but in the upper part of the Rangitikei, unless I have mistaken what I suppose to be the representative of the coal shales of the Whanganui, one might expect to find the coal seams cropping out. I hope that travellers ascending the western rivers will be on the look out for coal seams. Should they be found where I expect, in the Rangitikei, it may be well to bore at the Manawatu to ascertain if they there underlie the blue clay.
At various points on the Manawatu I observed a carbonaceous seam which, perhaps, might be dignified by the name of lignite. It is probably of the same age as the ancient forest of Whanganui, and apparently of no value.
As I suppose no one will be bold enough to sink through a great thickness of tertiary rocks on the chance of finding gold beneath, the country possible for gold is now pretty nearly reduced to the main range itself, and its few grauwacke outliers. That part of it which I have seen at the gorge of the Manawatu looks neither better nor worse mineralogically than the country round Wellington, except that the whole country is covered by dense bush, and that the gullies which came under my observation were mere acute angles without any level bottom.
Any one wishing to explore the main range from the Manawatu should form a depôt at Raukaua, about five miles below the gorge. This is the residence of Hiriwhanu, the principal chief on the Manawatu, who we found very civil.
At Otaki I examined some specimens which had been brought in lately by an exploring party from the mountains, and they are the most favorable looking for metals that I have seen, although it would be hard to say what metal to expect. There were some good specimens of quartz, some iron pyrites, serpentine, an undeniable slate, and a small piece of rock with very granitic constituents An exploration from Otaki would be desirable, although it is, perhaps, getting too late in the season to go far into the mountains; but where the hills are covered with so dense a forest it will be very difficult to make sure of the ground.
I hardly think that in my former report I have enlarged sufficiently on the Whanganui coal. Although it is probably a tertiary coal, yet it has every appearance of being a valuable product. Mr. Soulby, of Whanganui, has promised to procure enough of the Tangarakau coal for purposes of analysis, and I have written to Topini Te Mamako to send down some kits of the Ohura coal for the same purpose.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.His Honor I. E. Featherston,
Superintendent of the Pro-of Wellington.
P. S.—On further consideration of the fossils which I have collected, and the non-appearance of coal strata in the Upper Rangitikei, I am inclined to think that I may have mistaken the relative position of the blue clay, and the rock with linear bands of modules, in the cliffs of that river. It is quite possible that at some point obscured by vegetation, or deceived by a slip, I may have drawn an erroneous conclusion, that the latter rock underlaid the blue clay; I am now inclined to think that this rock is the upper sandstone. In that case the coal seams could not be expected to be exposed
and must be sought for at a lower level in that district, which will be below the level of the bed of that river. It is to be desired that the tertiary rocks should be classified, and their relative ages fixed.
Wellington, March 19, 1862.
Sir,—I have the honour to submit the following report, of the capabilities of the various districts, which I have examined during the last three months, for agricultural and pastoral pursuits.
My investigations have extended over the Western division of this Province, up to the boundaries of the Provinces of Auckland and Hawke, and within no great distance from the Province of Taranaki.
It will be most convenient for purposes of description, and will, I think, make the subject clear at a glance, to divide the country described into three zones.
The zone, or belt, of open country, naturally covered by fern, flax, toe-toe, and shrubs, which extends from the sea shore, at Rangitikei and Whanganui, both inclusive, to an average distance of, say ten miles inland. As this fertile belt of country is well known, it will be needless further to describe it. It appears to extend beyond the limits of this Province as far as Taranaki.
The zone, or belt, of forest, averaging perhaps from thirty to forty miles in breadth, (in a straight line), extending from the first zone to the open country in the interior, and sweeping round from the flanks of Ruahine to the Province of Taranaki. This immense forest grows upon a broken country, composed of sedimentary tertiary rocks, much cut into by denudation. The soil seems to be in general of good quality, and it appears to me, that if settled upon a judicious plan, there is much of it capable of being brought into profitable cultivation, more particularly considering the warmth and genial climate of its sheltered valleys. In the valley of the Wangaehu there is said to be some extent of open land in the heart of the forest.
It is imperative that a road, or roads, should be formed through this forest country, before either colonists or Maories can develop the resources of—
The zone, or centre, of grass. On emerging from the forest, in the Patea country, towards the head of the Rangitikei river, I found an open, rolling, grass country, apparently extending from thence as far as the eye can reach, to the northward, but interspersed with belts and patches of bush. There is some fern, but the characteristic of this zone is grass, and the herbage put me in mind of some runs in the Middle Island. Here is found the spear grass, which is unknown at Whanganui, and other plants which are common in the South.
Thence to within about ten miles from the base of Ruapehu, is a good grass country, but there the geological formation changes from a tertiary shelly rock to volcanic sand, pumice, and lavas, and the grass changes from a good sward to a scanty herbage. The rule seems to be, in opposition to the general notion, that the tertiary rocks here give a good, the volcanic rocks, being chiefly pumice, a barren soil. The elevation of the country is also great, and the plateau below Ruapehu bears every evidence of a severe winter climate.
From the point of departure of the Wangaehu and Waikato rivers, on this plateau, the slope of the country Northward falls rapidly towards Lake Taupo, and the vegetation improves, but fern also increases.
The open country appears to surround the volcanic chain, and on leaving Lake Taupo our road to the Westward lay through grass land, until entering the forest, which extends to the Whanganui river. This grass country on the Western side of Tongariro is called the Rua Mata plains: the soil is pumice, but with a good admixture of vegetable mould.
At a rough estimate I should make the gross extent of the open land of the interior, within the Province of Wellington, amount to about 1,200,000 acres; bounded by the zone of the forest on the South and S.W., the Whanganui bush on the West, the boundary line of the Province on the North, and the Western flanks of the Ruahine and Kaweka ranges on the East;—but I must make a very large deduction for the volcanic chain of Ruapehu and Tongariro, the comparatively worthless land at its base, and for interspersed forests and swamps throughout the district. Perhaps 500,000 acres may be a fair estimate of what is really available for pasture, but as there is no correct map of the interior this calculation must be taken “cum grano salis.”
A difficult question is that of climate, which would require the experience of a winter residence to answer correctly. All the inhabitants agree in stating that the plateau under Ruapehu is covered deep with snow during the winter months, and that stock could not then be kept there. On the other hand I saw no indications of severe winters in the Patea country, and sheep seemed to thrive well on the hills above Taupo, in the direction and about the level of the Rua Mata plains. Experience will be the surest guide on this point.
It appears impossible to work the grass country of the interior to any advantage, until a road is made to connect it with the coast, for at present, there is no possible means of getting wool out for shipment, at a profit; and although the Natives succeed in driving a few quiet cows through the track by the Rangitikei to Patea; this line may be considered to be impracticable for cattle without an improvement in the road.
The trade of the interior will doubtless eventually be divided between Whanganui, Napier, and Tauranga. The latter place is able to do a good deal of business already in the northern part of the district; but until a road be made through the forest Whanganui is precluded from taking any advantage of her position beyond the small amount of trade afforded by the canoe navigation of the rivers.
The Natives at Taupo appear to be unable from distance and absence of roads to bring any produce to market to pay for European goods. They are therefore constrained when they wish to purchase clothes or luxuries to take their departure for one of the English settlements on the coast, and there work for wages until they can buy what they require, and from the impossibility they find in carrying wool to the coast they propose to manufacture their own blankets in the interior.
I have already pointed out the probable lines for several roads through the forest, but perhaps that which would be more useful at first would be an improvement of the present line by the Rangitikei into the Patea country, and I believe this might be done at a very moderate outlay.
The Patea country, once reached, is easily traversed on horseback, and with a few small bridges and cuttings would be open for drays; but the line of road from the sources of the Wangaehu to Taupo is much more difficult, as the mountain torrents are there numerous, and their channels often lie in deep gullies, which would interfere with the passage of wheeled vehicles.
The capabilities of the West coast country may be summed up as follows:—
The coast zone. Agriculture and artificial pasture.
The forest zone. Artificial pasture, arboriculture, vineyards? and small cultivations.
The open country of the interior. Pasture only, except sufficient cultivation for the support of the inhabitants.
With regard to the Manawatu district, it has also its zones, although not so distinctly marked as those to the Northward.
Sandy flats, swamps and sand hills, with some rich alluvial, but flooded land, extend for perhaps ten miles inland.
Undulating grass and other open land, forest, swamp, and alluvium.
Forest to the foot of the ranges. The ranges themselves, at all events at the gorge, are also covered by a dense and unbroken forest, which continues on the level land to the Eastward.
Although the possibility of the introduction of the salmon to the Southern hemisphere is still problematical, yet, as another attempt is about to be made to naturalize that valuable fish in Australia and Van Diemen's Land, I would observe that the Western rivers of this Province seem admirably adapted for its propagation, as their waters are probably sufficiently cold, particularly those of the Whanganui, fed as those of the latter are throughout the summer by the melting snows of Ruapehu. Apart from the interest attached to the capture of this fish and its value as food, its successful introduction would involve large annual returns and much wealth.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford.His Honor I. E. Featherston,
Superintendent of the Province of Wellington.
List of Rocks collected during the Expedition.Whanganui river—
Igneous boulders—Products of Tongariro and Ruapehu.
Greenstone with crystals of hornblende.
Lava with felspar crystals.
Lava with glassy felspar and pyrdzeno.
Lava with pyroxene and white felspar.
Porphyritic felstone, with conchoidal fracture.
Do. with reddish felspar.
Felstone.
Tufa.
Pumice.
Obsidian.
Vesicular lava.
Felstone porphyry.
Hornblende rock.
Laterite.
Basalt.
Boulders of crystalline sandstones and slates—
Siliceous slate with veins of quartz.
Quartzite.
Altered grit,
Conglomerate.
Crystalline sandstone.
Quartz.
Tertiary—
Sandstones, indurated clays, shales, limestone, drift gravel, lignite.Bed of Waipare, tributary of Whanganui—
Silicious slate with quartz veins.Rangitikei—
Silicious slates and crystalline sandstone gravel with a few boulders of igneous rocks.
Tertiary—
Sandstones and indurated clays, drift gravel, lignite.Manawatu Gorge—
Silicious slate.
Do, with quartz veins.
Altered slate.
Jasper.
Jasper and quartz.
Crystalline sandstone.
Tertiary—
Sandstones and indurated clays, lignite.Otaki—
Silicious slates and crystalline sandstone gravel.
Slate.
Carbonate of lime (veinstone)
East Coast country, valley of Upoko Ngaruru—
Igneous, plutonic.
Hornblendic rock (not “in situ.”)
Thanks to the exertions of Mr. Walter Mantell and the opportune arrival of Mr. E. Layard, I am enabled to publish the following list of the fossils collected by me, and named by them.
Whanganui river—
Between Pilot Station and Kai-iwi-Blue clay—Venus, trochus, terebratulata.
Caves—Base of upper sandstone, and upper part of blue clay—Ostrea, venus (2 species), pectunculus, artemis, crassitella, pecten, corbula, modiola, trochus, crepidula, mixed with gravel of quartz and other pebbles.
Long reach above the junction of the Maunga-nui-te-au—Base of upper sandstone—Pecten, venus, scutella, balanus, terebratula, crassitella, and one or more univalves not in sufficient preservation to be identified.
Utapu—Base of upper sandstone—Ostrea.
Puketapu—Blue clay—Pectunculus, balanus, artemis, calyptræa, mytilus, flustra, struthiolaria, voluta, crepidula, cucullæa, corbula, serpula, dentalium, crassitella, cultellus? mixed with some gravel.
Paparoa—Base of blue clay—Struthiolaria, turritella, pectunculus, venus, voluta, ostrea, dentalium, cucullæa, crepidula, tooth of lanma, purpura, crassitella (2 species), ancellaria, crustacean, balanus, artemis; some of these fossils are distorted.
Patea country—
Hautapu and Moawhanga rivers—Probably upper sandstone—Trochus, littorina, venus (2 species)
Manawatu river—
Near the Gorge on both sides—Upper sandstone—Venus, pholadomya, traces of lignite.Upper course of Oroua river—Terebratula, pecten, natica, tellina. (Collected by Mr. Stewart, surveyor.)East side of Gorge—Ahuriri limestone—Fossils comminuted and cannot be identified.
The fossils from the Rangitikei have unfortunately not yet arrived in Wellington. Pecten is a characteristic fossil of that river.
Stream falling into Whakatamahine, which is a tributary of Wainuioro, which is a tributary of Pahaua—Blue clay—Solarium, serpula, cucullæa, fusus, (collected by Messrs. Beetham).
An examination of the above list will prove the correctness of the classification of the tertiary strata which I have given, and will show the connection of the blue clay on both sides of the island.
Note—I am informed that the limestone at the base of the blue clay is likely to make a good cement.
Printed under the authority of the Government of the Province of Wellington by N. Sutherland, Printer for the time being to such Government, 1862.
Council Paper.Province of Wellington.Session X.Geologicaland otherReports,By the Hon. J. Coutts Crawford.
Printed under the authority of the Government of the Province of Wellington, by Thomas McKenzie and James Muir, Printers for the time being to such Government.
Geological and other Reports.
Wellington, August 23, 1862.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
As the question has arisen how the Government of the natives may be conducted from Wellington, it may not be premature to consider the best means of opening inland communication from this place, with the great centres of Maori population in the valleys of the Waikato and the adjoining rivers.
There appear to be four routes by which this object can be effected viz.:—
1st. By the present lines of communication between the interior and Auckland, and thence by the mail steamers to Wellington.
2nd. By one of the routes through the forest country near the Rangitikei, or Wangaehu rivers, emerging on the open interior and thence passing to Taupo, and the North, to the Eastward of the Volcanic range of Ruapehu, and Tougariro.
3rd. By the way of Taranaki, either by coast, or inland, and thence to the Waipa and Waikato, valleys.
4th. By connecting the township of Whanganui with Na Huinga (or the junction) of Ngarue with the main Whanganui river, from which point there is said to be an easy road to Ngaruawahia.
The 1st route is inadequate and involves too much trusting to correspondence only.
The 2nd route ought at any rate to be opened for a horse road and the line by the Rangitikei, may be estimated, for this purpose, to cost as follows.
Felling and burning fifty miles of bush at £1. 5s. per chain, 4000 chains £5000, exclusive of some small bridges and cuttings.
The 3rd route will probably be opened as far as Taranaki, for its local value alone; but its direction is too far to the West, and the distance consequently is too great, for rapid communication with the Waikato.
The 4th route (if practicable) will be the best and most direct route of any, that is to say if the Maori information be correct, that from Na Huinga,
Na Huinga means the junction.
an easy line of road leads through an open country, with only one short bush to pass through, to Ngaruawahia.
The distance of Taumarunui (the pa at Na Huinga) from the township of Whanganui, I estimated at 170 miles, by the bends of the river; taking a rate of speed six miles an hour. This I am inelined to think, is perhaps one mile an hour under estimated.
The descent occupied (while actually underweigh) 29 hours 20 minutes, so that 200 miles may be about the mark. The distance in a direct line on the chart, would appear to be about 70 miles only.
If a road be practicable, the length required may perhaps be estimated as somewhat over 100 miles. This line would form one of the most valuable links in New Zealand. It would directly open the Waikato country to Cook's Strait, and would intersect the line of Ohura, which would open the Mauiopoto country, and the high plateau of the interior being avoided, the road would be always open.
Whether this line be practicable or not can only be ascertained by a skilful engineer devoting a summer to its investigation. The difficulties appear considerable; but I think it extremely probable, that by a little judicious twisting and turning, the ridges may be headed and a line of road obtained. It would be chiefly side cutting.
Taking Whanganui as the pilot of communication, the improvement of the route between that port and Wellington remains to be considered. For the present this is an easy day's journey by steam—but as an inland road is absolutely required to open up the country, I, for one, shall not be satisfied until I see a Railroad running up the West Coast. I believe that a Railroad, as recommended by Mr. Fitzgibbon, can be laid down, on that coast, much cheaper than a macadamized road could be constructed. One reason will suffice, viz.—that a large extent of sand or swamp, could be traversed by a railway on short piles and sleepers, without further outlay, or movement of soil.
From Wainui to Whanganui, the difficulties, except for bridges, are trifling. From Wellington to Wainui, although some preliminary investigation is required, there would seem to be no real obstacle, considering what the Dun Mountain Railway has achieved.
Should the Native Land Bill become law, there would appear to be no object in delaying the construction of railways because they pass through Native Land although perhaps financial arrangements for their promotion might require some novel application.
I have the honor to be,Sir,Your most obedient servant.James C. Crawford.
Manawatu, October 21, 1862.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
As an examination of the rocks of the Province of Wellington has hitherto only resulted in the discovery of small samples of gold, and has failed to discover that metal in workable quantities, the question arises in what line, or direction, we ought to expect to find gold in the Northern Island.
Some years ago and before the opening of the Otago Gold Diggings, but subsequent to the discovery of those at the Buller river, I pointed out in a letter to the newspapers, that a continuation of a line, through the Gold districts of the Middle Island to Coromandel, would intersect the country lying between the Whanganui river and Taranaki and that on that line, supposing the tertiary rocks did not entirely cover the country, the gold bearing rocks would probably be found.
This line is in a bearing of about N.N E, and S S.W., nearly the line of the Magnetic Meridian.
Subsequent observations and discoveries, tend to confirm the probability that this is the true line, or rather zone, in which to look for the gold bearing rocks.
From the specimens which I have seen from Otago, from the Buller river, and elsewhere in the Middle Island, micaceous and talcose schists and micaceous rocks generally, associated with quartz, seem to be those most favourable for the finding of gold. Now the rocks of the Western ranges of the Middle Island are very micaceous, while those of the Eastern Ranges, minerologically the same as the main range of the North Island, contain little mica, and are principally silicious slates and crystalline sandstones, associated with serpentinous rocks.
There appears to be a remarkable parallelism in the ancient New Zealand rocks. The main range of the North Island, in which Wellington is situated, traverses the Island in a N.N.E. direction from Cook's Strait, and reaches the sea in the Bay of Plenty about six miles from the East Cape. This range, having rocks of similar mineralogical character, crosses the Strait, and proceeds in a curve into the Canterbury Province, and so on to the Southward. Behind it, in the Otago Province, the gold bearing mica schists would appear to curve round somewhat to the Eastward. The Eastern range, composed principally of silicious slates, and crystalline sandstones, all highly inclined, appears to contain some gold, but none has yet been found in payable quantities.
As far as my examination extended in the Taupo country and at the head waters of the Whanganui, the few ancient cocks which I found there, either “in situ” or as boulders, consisted only of siliceous slutes, or semi crystalline sandstones,—no mica schists, nor gneiss, nor granites; but the line of my journey was still to the Eastward of what may be the gold bearing zone.
As evidence of a gold bearing zone running through the North Island, taking the Coromandel as a starting point, we hear of gold quartz being discovered at the Wairoa, not far from Auckland,—next, I am credibly informed. that gold quartz is common in the Hangawera range, which separates the Waikato from the Thames valley and next, I have the authority of Sir George Grey for stating, that a rich piece of gold quartz was brought to him by a native from Titi Raupenga, a place distant a journey of a day and a half N.N.W. from Pukawa on Lake Taupo. I have also to add to this, information which I have received from Mr. Fitzherbert, that samples of the iron sand of Taranaki, sent by him to be analized, were reported to contain traces of gold.
Should the above view of the line of the gold bearing rocks seem theoretically good, the question arises in which way the existence of gold can best be proved. I believe that point can be most satisfactorily arrived at by traversing the gold bearing rocks in the Province of Auckland, from the Coromandel towards the Waikato and Waipa districts, and finding how far they can be traced to the South.
I would also recommend a thorough
investigation of the Taranaki iron sand, by sinking to some depth, and by any other means that observation on the spot may suggest.
I would here point out, that although volcanic regions are generally considered unlikely for metals, yet immense areas of the Gold Fields of Victoria are covered by a sheet of trap, and as yet I know no reason why the age of eruption of Mount Egmont should not be the same as that of the extinct volcanic region of Victoria, and therefore infer the possibility that the Trachytes of Taranaki may cover gold bearing drifts.
Again, with regard to gold drifts, Mr. Selwyn reports three distinct gold drifts in Victoria, the oldest being of miocene age. Now although the West Coast of this Island is covered to a considerable thickness with sedimentary tertiary rocks, the oldest of which is probably of miocene age, there is no impossibility that a gold bearing drift of about the same age, should underlie these marine formations. For supposing the gold bearing rocks to lie beneath, they are likely to have been much abraded, during the depression preceeding the deposition of the tertiaries.
The supposed gold bearing zone, commencing at Coromandel, will cross the courses of the rivers Thames and Waikato, pass through Otawhao and through the Waipa valley, traverse the country lying between the Whanganui river and Taranaki, and so on to the Nelson Gold Fields across the Strait. The southern part of this zone in the North Island is very much, perhaps entirely, covered by tertiary rocks, but I have reason to suppose from the evidence previously given, and from other information, that in the Auckland Province the older rocks may be more exposed.
I have the honor to be,Sir,Your Obedient Servant,James C. Crawford,
Provincial Geologist.
Wellington, December 13, 1863.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,
I have the honor to inform you, that on the 8th November ultimo, I discovered a series of strata on the shores of Porirua Harbour, containing impressions of plants and carbonized substances. There are at least six of these strata, of various widths of from fourteen, to two or three feet; and with the associated shales and sandstones they make up a thickness of at least 800 feet,
I have strong reasons for supposing that these strata belong to the true carboniferous era, but, as I hope to be able soon to obtain the opinion of an eminent palæontologist, it may be as well to defer their further consideration for another report. The locality is between the Peninsula of Tutae Manu and Duck Creek, on Porirua Harbour.
In an endeavour to trace this series to the Belmont road and the Hutt, I have found a fossiliferous stratum on the above named road, which it is to be hoped will throw some light on the age of the rocks.
On my return from this latter expedition, I observed some very mineral looking pyritous quartz, at a point which the roadmen are cutting down, on section No. 14, Harbour District, on the south side of the big slip on the Petoni road, Pyritous quartz has long been known to exist here, but perhaps this is the first time that a section of the rock has been so well exposed.
Dr. Levy, (a French Geologist who has been residing here) very kindly undertook the analysis of a piece of this rock and his report is, no gold, but containing sulphide of antimony, cobalt, iron and mica. Another specimen he reports rich in chromate of iron.
Now the effect of this discovery is much greater than may appear at the first glance, for it proves the existence of mineral veins in the rocks of this district, a point hitherto undetermined. The minerals discovered may also be looked upon more as indications for the discovery of more valuable metals in the same or other lodes, than as being valuable in themselves, although chrome and perhaps cobalt if found in sufficient quantity on the shores of this harbour would doubtless prove valuable exports.
The quartz at the point indicated is laminated and corrugated, and a similar quartz is found at many different points. On the hills above, I think I made out several lodes, also on the Ohariu road, behind Dr. Taylor's the same veins appear to crop out. I have heard of similar quartz in the Ohariu valley and at Terawiti, and I think I also found it at Waikanae.
As the discovery has taken place on private land, and as most of the land in the district has been sold, perhaps the Government cannot do more than call the attention of the public to the fact.
At the point of discovery on the Pe-
toniPetoni road there is at least one lode of some 14 feet thick, and I think the roadmen are likely soon to lay bare the face of another. These might be easily proved on the level, by simply driving into the hill, but proving in depth would of course be more expensive Possibly a careful examination might show a series of parallel lodes, all of which might be proved on the level by one drift at right angles to their direction.
I may state that Dr. Levy was strongly impressed with the idea that the quartz ought to be auriferous, and although he failed to find gold in the sample operated upon, yet he thought it likely to be found in others.
Should indications of metals and mineral veins continue to be discovered, the necessity of having the services of a good and trustworthy analytical chemist, will be very much felt.
The schistose rock adjoining these quartz lodes would appear to underlie the soft sandstones, which may again underlie, or else form part of, the series of the carboniferous rocks of Porirua Harbour.
I have the honor to be,Sir,Your most obedient Servant,James C. Crawford,
Provincial Geologist.
Analysis By Mr. Thomas Dawson Triphook.Christchurch, March 18th, 1863.
Specimen from Pitoni Road, Wellington, examined by blowpipe.
Supposed to be micaceous iron,—resembles sulphuret of antimony, or graphite.
Infusible per se;—fuses with difficulty, and moderate ebulition to a clear glass before blowpipe with borax; no fumes of antimony, arsenic, or sulphur; streak, shiny black; streak powder, steel gray; hardness 1–2.
Hence the streak being black and streak powder grey, and not red, as in specular or micaceous iron,—the absence of fumes and its perfect infusibility per se, simply whitening before the flame, and having the property of distinctly soiling paper under very moderate pressure, together with its low degree of hardness and physical appearance,—lead me to pronounce the mineral to be an impure graphite, containing a fair per centage of iron, as appears from treatment with H.CI., acid and ammonia, which gives the usual brown precipitate of oxide of iron.
Examined carefully for antimony and crome iron, and found no trace of either.
(Signed)Thos. Dawson Triphook.
Wellington, January 12th, 1863.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
I have the honor to report that having procured the services of Mr. D. McEwan, M.P.C., and having engaged two active young men to carry provisions, we left the Upper Hutt on the afternoon of New Year's Day, for the double purpose of obtaining a geological section thence to the West Coast, and of exploring the little known forest country in that direction.
Having previously received information from Mr. George Swainson and others, that a considerable stream fell into the right bank of the Hutt, nearly opposite but rather above Petre's Mill, I considered that the valley of this river, the Akatarewa, would afford the most favorable route for expleration.
We crossed the Hutt opposite Petre's Mill and passing to the northward over a considerable extent of level land, on which are situated Maori cultivations, encamped for the night on the banks of the Hutt, not far below the junction of the Akatarewa. Here the Hutt can be easily fo-ded in many places, and should a bridge be required, a rock foundation can be obtained on both sides. The prevailing rocks are slate and semi-crystalline sandstone, the river about one chain broad. Here I found a boulder with plant impressions similar to those of the Porirua harbour, while lower down Mr. McEwen found a handsome agate pebble. I had previously been shown a specimen found in this neighbourhood, of the latter, polished on one side, from which I concluded that it had come from Europe; but this fresh discovery leads one to suppose that these pebbles will be found in the vicinity.
Our height above the sea, at first camp, by Aueroid Barometer, was 218 feet.
On January 2nd we started at 7.30 a.m., and at 8 a.m. reached the banks of the Akatarewa. It is here a river more than one third the size of the Hutt above the junction and shut in by black birch hills, which we scrambled over until 10.30 a.m., when we opened a valley, say
one third of a mile wide, with good flats and terraces on both sides. The black and white birch of the hills here gave way to totara, matai, rimu, &c., and on the hills rata were in full bloom.
At. 1.45 p.m., we crossed a considerable tributary coming from the westward, probably the stream which the Maories have described to me as running from the range at the back of Paoatahanui. Here there is a good deal of level land and the distance from the Hutt, in a straight line, may be two to three miles. Soon afterwards we saw wild cattle. During the afternoon we left the first valley and contended with the hills of the second gorge, wading the river constantly. We encamped for the night in the second gorge having attained an altitude of 509 feet. Our course during the day is estimated at North (mag.) distance say five miles. Mr. McEwen, whose knowledge of forest land is extensive, estimates the level land of the first valley at 700 or 800 acres. Some of it is flooded, but a great deal is on terraces beyond the reach of floods.
The rocks traversed during the day were mostly semi-crystalline sandstone, state and drift gravel, the latter sometimes 50 or 60 feet above the level of the river. The ranges in sight appeared to be about 800 feet above our level.
On January 3, we started in a drizzling rain which cleared off as the day advanced. We soon emerged from the second gorge into the second valley, in which are large terraces and flats, estimated by Mr. McEwen at 1500 acres in all. The hills also appeared lower. The soil is good and the timber principally rimu, kahikatea, rata, rewa rewa, and tawa, with some totara. The height of our dining place was 682 feet, which may be taken as the mean height of the valley. The prevailing rocks in this valley are slates, sandstones, with plant, impressions, laminated slate and quartz, and serpentinous rocks. The mean strike about North and South (mag.), Strata vertical. Found a boulder of laminated quartz similar to that of Pitoni road; drift terraces were observed at least 750 feet above the sea level, also a spring depositing oxide of iron, falling over a serpentinous rock. After passing the slates we again met sandstones and at 4 p.m. passed a good sized stream falling into the left bank, afterwards a smaller stream falling into the same side. Encumped at the third gorge where the river descends rapidly from the dividing range. Here the river runs in a chasm, with almost perpendicular banks.
The upward direction of the course of the river to-day has been more to the westward. Course, say N.W. Distance travelled say seven miles; made good in a direct line four miles.
Height of third camp 877 feet.
At starting on January 4th we were obliged to abandon the Akatarewa, as its bed was now too inaccessible for travelling. We therefore made a course over the dividing range, alternately ascending and descending hills of from 500 to 700 feet above the valleys, the inclination being from 45° to vertical—the hills covered with black, white, and red birch, hinau, kihikatea, rimu, miro, toro, rata, and tawa. We attained an extreme elevation of 1606 feet, at which height we found the mosquitos more troublesome than in the valleys—during the day we obtained peeps of what we supposed to be the sea. Towards evening descended, and encamped upon the bed of a stream which proved to be a branch of the Waikanae, but so narrow was the stream, and so steep were its banks, that we had to proceed downwards for some time before we could find a spot large enough to encamp upon. Here and during the day were decided indications of a damp climate—the fallen wood was rotten and sodden with moisture, and it was difficult to get good firewood. Our course during the day was about N.N.W. Distance made good in a straight line perhaps three miles. Rock mostly soft sandstone.
On January 5th, we started at 7 A.M., and proceeded down the narrow defile, walking in the bed of the stream, and cutting our way through fallen timber, until at 10 A.M., we struck the main branch of the Waikanae, where it comes out of a fine and picturesque valley, on a hearing of due North; the level land in this valley, in sight, being estimated by Mr. McEwen at 1500 acres. The tributary which we had followed falls into the left bank of the main stream—the united waters are fully 3/4ths the size of the Hutt river. Proceeding downwards at 10. 30, passed a good sized stream failing into the left bank, the ranges decreasing in height as we approach the coast, but still very abrupt. The timber cousists of rata, tawa, kahikatea, rimu, pukatea, fuschin, mahoe and a few totara—nikau palms began to appear, and thistles on the bank of the river (we found none of the latter in the second valley of the Aka-tarewa, but they were present in the valley nearest the Hutt). In the Waikanae we observed a good many small fish, but only saw one in the Aka-
tarewaAkatarewa. We now met with mobs of cattle and pigs, both wonderfully quiet. The prevailing rocks are sandstone, with a good deal of slate, and I again found boulders of the laminated quartz, similar to that of the Petoni road. At 2 P.M., we emerged from the hills upon the coast country, but found some difficulty in getting clear of the bush; however, when we least expected it, we came to an opening near a pa, and reached the Hotel at Knocks at 4 P.M. Our course this day was about N.W. Distance made good say five miles. Total distance perhaps nine miles. The Waikanae river within the hills is very picturesque, and (at all events where we descended it) can be forded in every direction and it runs over a comparatively smooth and even bottom.
The question now is the consideration of the value of the country discovered; and first I may state that no real engineering difficulties appear to exist, to prevent the formation of a road from the Upper Hutt to the West Coast, even should the dividing range be surmounted on a more northerly line, and the road be brought out at Otaki, instead of at Waikanae; but I fear that the expease would be serious, and would hardly be repuid by the sale of land in the district.
The plan that suggests itself to me is this, that advantage should be taken of the natural growth of valuable timber to pay the expense of a road for opening the valleys, by selling the right of cutting the timber for a certain number of years, on the condition of making roads through the District. A tramway for getting the timber out would probably be more easily and cheaply made than a road). The valleys would then be open for settlement in small farms, and afterwards the best line for a connecting road over the dividing range might be decided upon and made.
You will however perceive from the heights given, that no diminution in the altitude of the West Coast Road is likely to be attained by this route. I make the height of the summit level of the road over Paekakariki hill, by a mean of three observations, about 766 feet. Bearing in mind that the height of the dividing range where we crossed it is 1606 feet, and that the level of the upper valley of the Aketarewa is 682 feet, I think it unlikely that a pass will be found over the dividing range, which will not considerably exceed the elevation of the present road over the Paekakariki hill. N.B.—As my Aneroid burometer has no attached Thermometer, the heights must not be strictly depended upon.
Supposing the road to come out at Otaki in a distance of 30 miles from the junction of the Aketarewa with the Hutt, then the distance from Wellington to Otaki by the Hutt would be about the same as by the present route, but the more northerly line would be a great saving in time to persons passing from the Hutt or the Wairarapa to the West Coast, or vice versa,
In a geological point of view I found what I may call the usual rocks of the main range in this section across the country, including the laminated quartz of the Pitoni road. Should we find workable minerals in the neighbourhood of Wellington we may look for a continuation of them there. In such a densely wooded country however, and so much covered by soil or by drift, it is impossible to make a satisfactory geological survey without devoting to it much time and outlay, and even then much might be overlooked. I found no traces, for instance, in the Waikanae river, of the quartz conglomerate of which I had previously found large quantities on an adjoining hill.
I had hopes of finding traces of Tertiary or other rocks, at the point where the hills meet the plain, but in this I was disappointed. A clay which is observed there is probably alluvium.
On the 6th January we proceeded southwards to the Horokiwi valley, and on the 7th returned to the Hutt by the Belmont road, apparently travelling along a line of strike of soft sandstone and slate rocks and finding the plant beds on this line also.
I have to thank Mr. McEwen, M.P.C., for his valuable and intelligent assistance, and the two young men who accompanied us, Wm. Parsons and Thos. Lowe, for their cheerful and active co-operation on a fatiguing journey.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford,
Provincial Geologist.
Wellington, February 11, 1863.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
After returning from the exploration of the Valleys of the Akatarewa and the Waikanae rivers, I started from Wellington on the 15th of January,
with the view of gaining an insight into the geology of the N.E. part of the Province, more particularly in the direction of the Puketoe range, and the country generally, lying between the Tararua range and the East Coast.
Leaving the drift gravel of the Wairarapa behind me at Masterton, I found on rising the hills towards the Taueru station, that I had entered upon the tertiary sandstone. This rock I found extending over the whole of the interior of the North-Eastern district, resting upon the blue clay except where some drift gravel intervened between the two, but the gravel is by no means largely developed in this district. Towards the East Coast I found a change of rock, but of this more hereafter.
This sandstone consists of a series of soft fine grained sandstones, fossiliferous and alternated with fossil beds almost approaching limestone, and is sometimes of great thickness in this district, seldom less than 500 feet, and in some places I think it must measure 1000 feet.
Some of its fossils are turritella, venus, dentalium, pecten, struthiolaria, I have no doubt that it is of the same age and character as the sandstone of the Whanganui river.
This formation, where found undisturbed, seems to lie very horizontal; but numerous hill sides have slipped into the valleys, there giving the strata the appearance, to the casual observer, of dipping in various directions and at high angles.
From the vertical nature of the sections in which this series is found exposed, it has been impossible for me to make any but a partial investigation of its different beds, and the same difficulty, you may have perceived in the cliffs of the Whanganui and other Western rivers.
The blue clay throughout this district does not show much of its thickness above the river levels.
Crossing the Manuka range, 906 feet above the sea level, the road drops down to the Valley of the Taueru, and thence on to the Taueru station.
Here I visited a very beautiful waterfall, formed by the waters of the Mangarei, a tributary of the Taueru. The stream falls over a ledge of the tertiary sandstone to a depth of about fifty feet, into a large circular pool. Hard fossiliferous beds of this sandstone form the rocks at the fall, the softer overlying beds, which are found in an adjacent cliff, having been denuded.
I may here state that there is a remarkable parallelism between the effects produced in this district and in that of the country inland on the Whanganui and Rangitikei rivers, inclusive. In both districts are the tertiary sandstones largely developed, and in both have these nearly horizontal strata been broken up by denudation, into very rugged surfaces.
Many of the beds of the tertiary sandstone are extremely soft, and therefore liable to be rapidly worn away; some of them, indeed, on being struck by a hammer, instead of breaking into fragments, crumble and run down into pure sand; and water poured upon them passes through as in a sieve.
At the Taueru pieces of maine fossils were shewn to me as quartz; and I found that generally throughout the district calc spar, white limestone, or, as I have said, even fragments of fossil shells, were supposed to be quartz.
Some very perfect “pecten,” from the top of the Maunga Pakeha range, were presented to me by Mr. Varnham, for the museum in Wellington.
On the 19th January, I left the Taueru station and proceeded up the valley of that river, the Forty Mile Bush lying about three or four miles on my left and here covering a very broken country.
The road leads past Mr. Nicholl's, crosses the Taueru, and ascends the ridge on the Eastern side of that river. My estimate of the height of the Taueru station above the sea is 427 feet. The ridge just mentioned rises to 1100 feet, and the Manawa hill next to it, above a run which rejoices in the euphonious name of Boggley Wallah, to 1179 feet. Here one looks down upon Messrs. Jeffs and Riach's head station, and on the valley of the Whareama, with its level flats and swamps, while to the Northward may be seen the country drained by the Matai kuna, the Oahanga, perhaps also the Akiteo and here I could see plainly enough that all within view was of tertiary age, except the blue ridges of Tararua in the far distance.
At the Manawa hill, I was lucky in meeting Messrs. Spinks and Langdon, proceeding in the direction in which I wanted to go, viz, to Mr. Spinks' out station, Mount Pleasant, or Waitawiti. Our road passed over the highest ridge which I traversed in the district, viz Ngatakitura, which, by a mean of two observations, I make 1210 feet above the sea. From this ridge we descended to Mount Pleasant which is probably the highest inhabited European house in this island, being also
by a mean of two observations, 985 feet above the sea level. Notwithstanding the height, it is a very cheerful looking place and it commands an extensive view.
Leaving Mount Pleasant on the 20th January in the direction of Knight's station, we soon crossed the sources of the Taueru, passing therefore again to the Westward of that river, crossed a ridge and came upon the flats of the Waitawiti a tributary of the Tiraumea. As the latter river is a large branch of the Manawatu, we were now therefore, on Western waters.
We crossed another ridge and descended to the Tiraumea, at Knight's station, where the Waitawiti joins that stream. Our descent had been considerable, and Knight's house, by a mean of two observations, is only 414 feet above the level of the sea. Thus it appears that the gorge of the Manawatu must be considerably lower than that height.
The Tiraumea rises to the Eastward of the Puketoe range, runs to the Southward at first and turns to the Westward and Northward round the South end of that range, to join the Manawatu.
The country here is better and less abrupt than that lying further to the Eastward, but it is close to the forest of the forty mile bush.
When the forty mile bush road is made I should suppose it would be easy to open a branch line, by or near the Tiraumea to Knight's station, which would then form the easiest line to the Wairarapa for a good deal of the open country.
An open track of a few thousand acres, called Moroa, lies surrounded by forest, between the Tiraumea and the Taueru, about six miles below this.
The Tiraumea has at present very little water in it, but I am informed that in a fresh, canoes can ascend about three miles beyond Knight's.
In its bed I found a boulder with plant impressions.
I would now call your attention to the Puketoe range, which has been in sight for the last two days, and where we may be said to have arrived, for Knight's station is on its lower spurs. I believe a great deal has been expected from this range in a mineral point of view, perhaps because it is remote, and difficult of approach. My first view of its outline settled its character in my mind and a close approach confirms the first view.
It is clearly tertiary, of the same age and character as the country I had traversed, but attaining a somewhat greater elevation. The additional height and its scarped cliffs, lead me to suppose that it marks a line of fault, or slip. I need hardly add that metals cannot here be expected.
The ascent of the Puketoe from Knight's would be troublesome, although the distance is short. A succession of sharp wooded ridges intervene. It looks to be easier of access from the North East.
I do not suppose the height of this range to reach 2000 feet. Supposing it to be 500 feet higher than Ngatakitura, this would give an elevation of 1770 feet above the sea. There may be some open land on the top of the range, but the greater part is covered with bush.
At Knight's I found the blue clay, and on the ridges above, tertiary sandstone beds, with turritella, venus, struthiolaria &c., From Knight's it is impossible, at present, to get a horse through the bush to the gorge of the Manawatu, which, as the distance is short, might be easily rectified. The view this day extended over the sources of a number of rivers, the Tiraumea, the Taueru, the Whareama the Mattaikuna, the Oahanga, and perhaps the Akitio: open country to the Northward and Eastward, bush to the West, beyond which the Tararua is seen in the distance. On the Tiraumea there appears to be a good deal of totara.
From Knight's I returned to Mount Pleasant.
It had often puzzled me why the alluvium of the Wairarapa should be of such a different character to that of the Hutt, but I think I have now solved that problem. The Taueru from its source to its exit in the Ruamahunga, passes entirely through soft tertiary rocks, and I believe it to be from their degradation, that the peculiar character of the alluvium of the lower Rumahunga is derived.
On January 21st I left Mr. Spinks hospitable mansion, and proceeded to the Eastward, again crossing Ngatakitura and Manawa ranges. From the latter the road drops down to the valley of the Whareama, near the junction of the Makirikiri with that stream.
Here I again found the usual tertiary sandstone fossils. About two miles further down I reached Ngapapatu, Messrs. Spinks and Langdon's head station, which I make only 143 feet above the sea level. I now began to perceive signs of a geological change. Still proceeding downwards I crossed the Whareama, passed over a hill and descended upon the Tinui station, situated upon the flats of that stream, a tributary of the Whareama.
Immediately above the station is one
of those remarkable hills called Taipos, which I accordingly proceeded to examine. These hills have an extremely fantastic, picturesque and rugged outline, and at first give the impression of volcanic peaks, but on examination prove to be our old friend the tertiary sandstone, tilted at an angle of about 70° and dipping to the Westward; the harder parts of the strata sticking out in peaks, while the softer parts have been worn away.
On the top of the Tinui taipo I obtained turritella, venus, dentalium &c., Its height is 975 feet. Here also I found the Matai kuna taipo bore N 50° E, Buxtons taipos S. 20° to 30° W, and what I supposed to be Moore's taipos S. 15° W. W. It will thus be seen that the several peaks are nearly, but not quite, in a straight line.
Proceeding on the 22nd towards the coast, the road passes for a short distance up the valley of the Tinui, where I think I found the blue clay. Crossing that stream I ascended a ridge 828 feet high, where a fresh geological series is found, consisting of white limestone and calcareous grits, and in their midst, a fine grained greenstone, looking like a Syenite, which is doubtless the intrusive rock that has tilted the strata. It appears to have brought up the calcareous rocks, dislocating and tilting the tertiary sandstone at the same time.
If you refer to my report of October 24th, 1861, you will perceive that I describe calcareous rocks, highly inclined on Messrs. Baron's and Riddiford's stations, White Rock and Teawaite. I had now clearly found the continuation of the same series, and more than that I had found “in situ,” the dislocating and upheaving rock. The Hornblendic pebbles found in the bed of the Upoko Ngarurn must also have been derived from another variety of the intrusive rock of the same age, and from my previous traverse in that direction, to Messrs. Beetham's station, I have quite sufficient evidence to establish a line of dislocation and upheaval, extending about N.N.E. from the White Rock and Teawaite stations, the action along which line has exposed a series of calcareous rocks, thrown up the strata of the tertiary sandstone at an angle of 70°, and probably bent and folded a series of tertiary rocks which I was now approaching on the East Coast.
Descending from the calcareous ridge to the valley of the Whakatake the road follows that stream to the sea, and thence South to Castle Point. We now find a series of thin and soft beds of sandstones and mudstones, cropping out on the beach and in the vallies, sometimes nearly horizontal, and sometimes inclined at high angles. What relation these rocks have to the limestones and calcareous grits, I am at a loss to determine, for I could not here find a section which would throw light upon the subject. My impression is that they overlie the calcareous rocks and at the period of dislocation were rucked up on the back of the latter by the force of the upheaving power.
In these sandstones and mudstones I found small seams of coal and numerous impressions of vegetation, but none clear enough to be enabled to judge of their age, but as the coal-seams appear to be lignite, or brown coal, I have little doubt that we may put them down as of tertiary age. In fact I believe them to be of the same age and character, as the coal shales of the Whanganui River, mentioned in my letter of February 17th, 1862.
The history and age of the calcareous rocks will I believe be best obtained on the Teawaite station, where they approach the sea. They must not be confounded with the upper tertiary fossiliferous limestone of Tepurapura and elsewhere, which seems to be found in patches only.
On January 23rd I examined the reef at Castle Point. This reef is a peninsula forming the shelter to the anchorage. Both it and the rock called the Castle are composed of calcareous sandstone, resting unconformably on the sandstones and mudstones just mentioned. In it I found venus, pecten, terebratula, ostrea, turritella, struthiolaria, &c. The reef, which is a ridge perhaps fifty feet high, is penetrated by a cave, through which the tide passes and in which the roar of the wind and waves is very striking. Between the reef and the Castle Rock, the sea has another passage through the rocks into a basin. The Castle Rock is of similar formation to the reef.
In the mudstones and sandstones on the shore I found plant impressions, and in consequence proceeded in the afternoon up the bed of the stream behind Castle Point in the hopes of falling in with some seams of coal. I went on as far as I could penetrate, perhaps three miles, finding plenty of plant impressions, but no actual coal seams.
Mr. Guthrie informs me that some years ago, one of his shepherds, who has since returned to Australia, brought in a handkerchief full of coal, (stating that there was plenty more where he found it) which burnt well and seemed of good quality, and which must have been found within three miles of the Castle; but unfortunately he had neglected to ask
him where he got it.
The coal question in the East Coast District may be put as follows.
My impression is that the mudstones and sandstones of the coast are of tertiary age and therefore if any workable coal seams are found in them, that the mineral will be of inferior quality, but there are the little known calcareous rocks to be considered.
Now, at the Kowhai coal fields in Canterbury, there are calcareous rocks in the vicinity similar to the white limestone of our East Coast, and although Mr. Haast, at the time of my visit to that coal mine had been unable to determine any connection between these rocks and the coal, yet he had a strong suspicion that they formed part of the series. Consequently, although I have seen no indication of coal among the calcareous rocks of the East Coast, except perhaps at Teawaite, I think we have at all events some reason to expect the possibility of its being found; and as from the broken nature of the country it might take years for one individual to explore it thoroughly, I would suggest that a reward for the discovery of the outcrop of workable seams of coal, might stimulate the perceptive faculties of shepherds and others, whose daily avocations lead them through the defiles of these regions.
On the beach here is some iron sand, whence derived it is difficult to say, unless it comes from the intrusive greenstone.
On the 24th January, Mr. Thomas Guthrie kindly accompanied me to point out some coal seams on the shore. Near the Nakaua river we found soft sandstones containing plant impressions and some coal seams about two inches thick. They were not continuous, but thinned out in a yard or two. The rocks are the same as those at Castle Point and dip slightly to the Westward.
Ascending from the beach, in about a mile, I again came upon the calcareous grits and the intrusive greenstone, both of which prevail in crossing the Trooper, the ridge separating the Whareama from the sea. 896 feet I make the height of this ridge.
From this range the Puketoe is visible, its tertiary character evident from this distance.
Descending from the Trooper, I crossed the alluvium of the Wharehama Valley, and ascended the hill next to Buxton's Taipo, composed of calcareous grit. The Taipo has a singular family resemblance to that at Tinui and also dips to the Westward. I thence descended to Telford's station, Awa toe toe, 136 feet above the sea.
Leaving Mr. Telford's on January 25th, I continued on the calcareous grits for about a mile, when the tertiary sandstone rocks again appeared, and I found turritella, venus, &c. The tertiary sandstone now continues all the way to Collins' bush, resting on the blue clay, or possibly in places on gravel.
The road crosses a ridge and descends upon Biscuit Creek, crosses another ridge and descends upon the Kaumengi, crosses a third ridge and descends upon the Taueru, crosses a fourth ridge and descends upon Te Ore Ore: the average height of the river flats being about 400 feet and of the ridges, where the road crosses, about 900 feet above the sea.
Reaching the Ruamahunga the upper sandstone has been left behind, and the drift gravel appears.
Stopping at Masterton for the night, I was informed that the plant beds of the East coast extends for a considerable distance up the Oahanga river.
In this journey I have settled the character of a large block of country, viz.,—the whole of the island within this Province lying to the N. E. of the Wairarapa, and between the Tararua and the East coast. It will of course be desirable to complete a traverse which I propose to make with you, from the gorge of the Manawatu to the Akitio river and the East coast, but as I have been through the gorge of the Manawatu, and as I have also been on the Rua Taniwha plains and at Porongahau, I may very safely venture to predict that in the above named traverse, we shall find nothing but the above described tertiary and other rocks.
In none of these tertiary rocks can metallic ores be expected, (although the intrusive igneous rock may contain a little gold), nor do I expect any in the limestones and calcareous grits, for the following reasons.
1st. Because I see no indications of mineral lodes among them.
2nd. Because, although I have been unable to detect fossils among them and therefore cannot as yet assign to them their geological age; if not older tertia ries, from their lithological character they can hardly be older than of Mezozoic age, and therefore, supposing them to be of that age, although coal may be looked for, one cannot expect to find any of the metallic ores among them, save possibly ores of iron, of which however there is no
appearance.
The date of dislocation and upheaval of these rocks would also, I imagine, militate against the argument of their containing metalic ores (there being no appearance of any previous disruption of these rocks which might have charged them with minerals). The intrusive plutonic rock must have penetrated them after the deposition of the tertiary sandstone, therefore probably in the Pliocene, or Post Pliocene era.
You will perceive that we have now established three nearly parallel lines of plutonic or volcanic action in this Province.
In the centre, the ancient rocks of the Rimutaka, Tararua, and Ruahine, with their spurs, folded and pressed together, and having a general direction of about N.N.E. true.
In the East, the calcareous and tertiary rocks, tilted on a line of about N.N.E. (magnetic) from the ancient rocks of Cape Palliser towards the Province of Hawke's Bay. In the West we have part of the volcanic chain of Ruapehu and Tougariro, ending abruptly, however, at the southern slope of Ruapehu, and perhaps I might include a fourth line in that neighbourhood, in the Kaimanawa range but it is hardly in the Province.
From the central chain on both sides tertiary rocks extend East and West. I have therefore narrowed the area in which metallic ores may be sought to the main central range above described, the Kaimanawa range in the Taupo country and the Aorangi range at Cape Palliser, save and except the chances of finding gold below, or in, the drift of the Wairarapa and the West Coast.
On the 26th of January, I returned to Wellington, with the expectation of finding a report from Melbourne, upon specimens of rocks which I had sent there for examination; in this I was disappointed, and as I had a little time to spare before the arrival of another mail, and found that some curiosity existed as to the results of a recent journey to the top of Tararua, by the valley of Wai Ngawa, I proceeded to Greytown on February 3rd, with the intention of making the ascent of that mountain.
However, after several days attempt to get hands to accompany me, I found that owing to the harvest and the bush fires I could neither get white men nor maories to undertake the journey at this time.
Mr. Thos. Kempton, who offered to go as guide, gave me however a very clear and intelligent account of his late journey. He appears to have travelled up the bed of the Wai Ngawa for three days, before emerging from the bush, aod at a great incline, he thinks often three feet rise for four in advance. He then came out upon a grass country, extending to the top of the mountain, the vegetation consisting of a new sort of tussac, the common spear grass and the broad leaved spear grass (no doubt the “Spaniard” of the Middle Island) and wild parsley, which I suppose to be anise. To any one who knows the Middle Island the vegetation speaks for itself. He had reached the zone of grass, above the usual forest zone.
Arrived at the top he saw range after range to the Westward, of the same character, with bald grassy tops above the forest zone, and apparently nearly, if not quite, of the same height as the range on which he stood which shut out the view of the West Coast.
It is evident enough that the grass country must be covered with snow all winter. If it can be made of use, Mr. Kempton recommends a line to be cut into it by a leading spur opposite Ray's. On the descent he found out a better line if road which would shorten the ascent by a day. He describes the rocks as similar to those of the Rimutaka hill.
As all the rivers on that side of the Rimutaka and Tararua bring down similar gravel, this was to be expected, as the parallelism of the formations is obvious.
During this journey I felt two shocks of earthquake. One on Febuary 4th in the Upper Hutt, about 7. 15. a. m. the other on the 7th at Greytown, about 2. 50. p. m. Both were rather smart shocks.
On my return to Wellington on the 9th I found the expected report from Melbourne had arrived, a consideration of which I will reserve for a separate communication.
I have honor to beSir,Your most obedient servant,James C. Crawford
Government Geologist
To His HonorI. E. Featherston,Superintendent of the Provinceof Wellington.Wellington, February 14th, 1863.
Sir,—In forwarding to you a copy of a report which I have received from Mr. Brough Smyth, of Melbourne, on specimens of rocks sent by me for examination, from various parts of this Province, I shall take the opportunity to point out
what my plan of operations has been, and also show wherein I agree with Mr. B. Smyth's very able and valuable suggestions, and where, from causes of which he would necessarily be unacquainted, his views cannot perhaps be carried out.
In proceeding with the Geological Survey of the Province I have thought it advisable, first of all, to obtain a general knowledge of the whole rock formations within its limits; so that when it became necessary to employ men upon the Survey, I might be able to go on with continuous work; otherwise they might have been frequently unemployed, waiting for me to know in what direction to turn.
The kind offer of the Honorable G. S. Evans, Postmaster General in Victoria, to submit specimens of our rocks to the “Savans” in Melbourne for examination, came in aid of my views, and is the more useful, as we have no analytical chemist in this Province, and that, should I attempt to assay minerals myself, it would take up much time, probably the results could not be relied upon, and even the necessary re-agents and laboratory plant cannot be procured without sending to Australia for them.
I therefore collected and sent to Melbourne specimens of rocks from many parts of the Province, but more particularly from these ranges, and awaiting the report, I made such excursions, especially those described in my last letter to you of the 11th instant, as, combined with my explorations last year, enable me to grasp all, or nearly all, the leading Geological features of the Province. By this means I have narrowed the area within which the search for minerals may be expected to be successful, to the main ranges of Rimutaka, Tararua, and Ruahine, with their spurs; the Aorangi range at Cape Palliser, and the Kai Manawa range in the Taupo country. I except coal, of which more hereafter.
You will observe in Mr. Brough Smyth's report, that granite appears among the specimens sent by me from the Upper Hutt. This confirms the opinion of that eminent geologist, the Rev. W. B. Clarke. Doubts, however, having been expressed, I have preferred waiting for confirmatory evidence before announcing the fact.
The theoretical proof which I gave in my letter of December 18th. 1861, of the existence of the “gold constants” in these ranges, is now confirmed by the discovery of granite, combined with the evidence of the ancient character of the bulk of the stratified rocks.
The granite is found in the ridge behind Mr. J. Brown's, in the Upper Hutt, which bounds on that side the Mungaroa swamp; and I have also found it on the Mungaroa Hill. It is very fine grained, and may easily be mistaken for a sandstone. It will doubtless be found nearer Wellington, and may come into use as a building stone. Near it is sandstone with quartz veins, and mudstones of two kinds, but I cannot yet say in what sequence.
With regard to metamorphic rocks, although the semi-crystalline sandstones and other rocks may be said to be of that character, yet as there are neither gneiss nor mica schists within these ranges, it will be advisable to abandon the term as applied to the rocks generally. The fact is, that the more the country is examined, the less metamorphic do the rocks appear.
Thin quartz veins appear to penetrate many of the rocks of these ranges, riddling them in all directions; but the larger quartz lodes are by no means so prominent as in the gold regions of Australis. That powerful lodes of quartz and other vein stones however traverse the rocks, every exploration tends to show; and I can mention one quartz lode fifteen feet wide and many others besides of considerable thickness. I believe the geological hammer now requires the aid of the pickaxe and crowbar, to expose the mineral veins.
Quartz lodes and other mineral veins seem principally exposed in the fractures of the anticlinal axes, which bears out my original impression that minerals will be found to lie deep, and this view will also affect the argument as to the locality of alluvial gold diggings.
If gold lies deep in the rocks while “in situ” the wearing away of these rocks (particularly as here in deep and steep vallies) will deposit it in the lower vallies only, and it may be plentiful there, while entirely absent from the higher ground.
It is suggestive that the rock taken from Mr. Barraud's well should resemble rocks from a district where sulphide of antimony and chrome iron are found, these being two of the minerals reported in the pyritous quartz lodes of the Petoni road. The sandstone with plant impressions, (No. 37,) from Porirua, being decided, on the high authority of Professor McCoy, as of mezozoic age, which
with regard to coal, means oolitic, (the age of at all events the upper beds of the Australian Newcastle coal seams); and the mudstones being declared Palæozoic and probably silurian, it follows that we have sedimentary rocks of two eras in these ranges, folded however together in such a way that I foresee great difficulty in drawing the line of demarcation.
Mr. Brough Smyth's remarks with regard to gold seeking show a masterly grasp of the subject.
A reference to my letter to you of October 21st 1862, will show that I have most faith in gold being found, in the North Island, in the continuation of a line from the Middle Island Gold Fields to Coromandel, and that the present evidence is in favor of micaceous and talcose schists as the best gold bearing rocks of New Zealand; but I have also strong reasons to show, why the search for drift gold in this Province should not be hastily abandoned. I will first of all dispose of Barraud's well. This well is sunk for a few feet only through a sandstone and a felspatho siliceous rock. These rocks were said to be intersected by a vein stone, which was covered with rubbish when I visited the well, and unfortunately on the following day it was bricked up. There is neither drift nor alluvium above the rock and only an inch or two of soil.
That gold dust might have been thrown into the well is possible; but the specimens sent to Melbourne were collected from the rubbish heap afterwards, and therefore not likely to contain any foreign mineral. I shall endeavour to make a further examination, particularly as more grains of gold are said to have been found in the neighbourhood and as I see some appearance of mineral veins close at hand.
I must now make some small corrections as to Mr. Brough Smyth's idea of our mountain chains. His view is, naturally enough, that our main ranges threw off spurs East and West, spreading across the country, whereas the remarkable feature is this, that the mountain ranges of the Rimutaka, Tararua, and Ruahine, including all the mountainous country in this neighbourhood, pass like a wall to the N.N.E. the spurs keeping on the whole the same direction as the main ranges. Of course one does not speak of a wall as built by a stone mason, or rigid line, nor do all the spurs and ridges adhere to a strictly N.N.E. course, but such is the main direction. The main strike of the rocks, being I should say about North (magnetic), with however many exceptions.
Most of the maps give an erroneous impression, by marking a range, curving from the Ruahine N.N.W. towards Taupo, which range does not exist, although the broken tertiary plateau may there reach an elevation of 2,000 feet.
For a description of the volcanic chain or block of mountains of Ruapehu and Tongariro, see my report of February 17th, 1862.
In its broadest part, from the coast opposite Mana to the Wairarapa, the main range does not appear to exceed twenty three miles wide. At the gorge of the Manawatu, the breadth following the curves of the river, is only about seven miles.
These mountains have assumed their form, less from upheaval than from lateral pressure. The strata are accordingly bent and folded upon each other, and the ranges are separated into a succession of sharp and nearly parallel ridges, culminating in height towards one or more central axes, but high and abrupt also at both sides, where the sea, or the tertiary rocks, meet them in a horizontal, or nearly horizontal line.
One consequence of this conformation is that the rivers, while within the ranges, run in ravines, rarely as in the instance of the Hutt, expanding into vallies.
If we take the valley of the Hutt as an anticlinal axis near the centre of direction of the range, we there find, in the central axis, the granite of the Upper Hutt and Mungaroa; but I have strong doubts whether we shall find it on the surface in the high parts of Tararua, although it may be assumed to form the hidden nucleus of that range. The basalts, like the diorite rocks of the Canterbury Province have not yet been found “in situ,” and are not likely to appear in a prominent way; and the only rock which I can venture to call lava, in this main range, is the red rock of the Rimutaka, (on the authority of the Rev. W. B. Clarke,) but where it is found, and elsewhere in these ranges, there are no signs of volcanic vents.
The stratified rocks, sand stones, mud-stones, slates &c., seem to, and I think will be found to continue to, occupy the main part of the ranges.
The accumulations of drift on the Eastern side of the ranges are fully equal to those on the West, and the tertiary rocks may be said, with some exceptions, to be of the same character and thickness on both sides of the main range. Mr. Brough Smyth, suggests as particularly worthy of immediate attention, the basins of the
Hutt, the Waikanae, the Otaki, the Manawatu, the Rangitikei, and the Whanganui. I would omit the word immediate in reference to the three last named of these rivers and substitute for their names those of the Ruamahunga, and its tributaries on the right bank, the Waipoa, the Wai Ngawa, the Waiohine and the Tauhere Nikau, (perhaps this last cannot be called a tributary.)
Although I should like to see the head waters of the Whanganui prospected, yet, even supposing the natives would consent, the expense of a party would be enormous in proportion to the work done. I only found about two yards of the ancient rocks during a journey of some hundreds of miles in that direction, and then in the bed of the Waipare, a tributary of the Whanganui, with the hills formed I believe of tertiary rocks, rising at an angle of 45° or thereabouts, on both sides, to a height of say 700 feet above the bed of the stream. I consider that the Upper Whanganui, must wait the progress of development of the gold fields from Coromandel through the Waikato country, which may throw sufficient light upon the subject.
The same remarks will apply to the Rangitikei River, and those rivers lying between it and the Whanganui. The heads of these rivers would answer Mr. Brough Smyth's idea of searching towards the sources of the streams, but a prospecting party to explore them must be fitted out and kept supplied at great expense and must be prepared for very deep sinking, and as yet there is no road.
With regard to the Manawatn, although old drifts may lie beneath the tertiaries on its banks, and may eventually be worth sinking for, if we find any reasons to warrant the outlay, the river itself is most unlikely for gold. It presents the curious feature of rising in the tertiaries of the East Coast, bursting through the main range and thence again passing through tertiaries to the sea. The whole course of the river through the ancient rocks does not exceed seven miles and its stream there occupies the whole breadth of the channel.
Immediate explorations of the Hutt, the Waikanae, and the Otaki, with the Eastern Rivers previously named, I particularly concur in, for reasons which I shall presently show.
This brings me to the main point o my argument, which is, if gold exists where is it to be found, as drift and alluvial gold?
I have endeavoured to show the character of the mountain range and from this it will be seen that in general the rivers while confined to the range, run in very narrow and perpendicular channels. After entering the mountains and ascending for a few miles the beds of the streams, the ascent is rapid in the extreme, the drift disappears and the waters rush over a rocky bottom, or over large boulders of the surrounding rocks, and therefore drift gold, if present, could only be worked for a comparatively short distance up the mountain beds of those rivers.
Old drift gravels and clays may certainly be found in various places on the hills, as on the Mungaroa hill to a height of between 700 and 800 feet, but in general the rock is covered by a thin stratum of soil only, and where that is he case of course there are no diggings.
If we then consider the great denudation which has removed the rock from these vallies, say in the glacial epoch, we may ask where has the material gone to? The answer is obvious. It does not lie, or only to a small extent, within the hills, but has been swept into the Wairarapa country on the East, into the basin between Kapiti and the main range, on the West; and into the Hutt Valley on the S.S.W.
If these rocks contained gold, most, if not all it of would follow the same route.
I therefore would suggest that in a search for drift gold attention should be first directed to a careful examination of the Valley of the Hutt; and also, what I have already hinted at, that the question of grappling with deep sinking in the Wairarapa and perhaps also on the West Coast should be considered, combined with an investigation of the river beds previously mentioned as far as practicable.
As Mr. Brough Smyth also suggests that gold may be looked for in unexpected formations. I would not omit the blue clay. Although it is a fossiliferous rock it has a great appearance of being a drift formation, and I submit the following theory of its deposit, say to the Eastward of the Rimntaka and Tararua.
Suppose great degradation going on in the glacial epoch, along the Eastern vallies of these ranges and the materials carried to the Wairarapa,—what would be the natural order of deposition? Why, that the heavier boulders would be left in the vicinity of the range, while the lighter particles of earth, clay and sand would be carried to a greater distance. As a consequence one may expect both deposits to be, in places near the line of demarcation, mixed together; and as the
lighter materials would be soonest exhausted, a deposit of gravel would latterly form over the clay. All this is carried out as far as I can yet speak. I have not as yet been able to find the blue clay to the Westward of the Ruamahunga, and the other conditions are found towards, and to the Eastward of that river. The elevated beds of gravel and blue clay, lying still farther to the Eastward, might not at that time have been upheaved by the force along the axis of elevation of the East Coast. Now, if the denuded rocks were gold bearing, most of the gold would be deposited, with the heavy gravel near the mountains, but lighter particles might accompany the blue clay to a greater distance.
On the other band the gravel and the blue clay may mark different, although consecutive periods.
The gold question will not be set at rest until the Wairarapa and the West coast plains are bottomed at several points.
Now that I have acquired a general knowledge of the rocks of the Province, I quite agree with Mr. Brough Smyth, that my attention should be directed to a minute investigation of some limited district. What I should now propose, with regard to the Geological Survey and apart from a search for gold, would be to make a detailed survey of the rocks of this range from East to West, mapping them and collecting specimens of every stratum taking for the purpose the only lines on which anything like a complete detailed survey can be made, viz, the scarped ends of the ranges from Terawiti to the Wairarapa and the next section further North, from the sea beyond Porirua, up the line of road to this harbour and thence over the Rimutaka to Featherston.
These traverses are absolutely necessary to show the sequence of the rocks and form a basis for further explorations, and as I find fresh mineral veins every time I cross the Rimutaka, we might expect to make some valuable discoveries. But I should like first to know the views of the Government as to the duty of the Government geologist in a search for gold.
Ought I now merely, as above, to point out the proper localities in which to look for that metal, and leave it to private enterprize to complete the research; or would the Government wish me to examine for the above purposes the localities indicated, viz the vallies of the Hutt, &c.
In the latter case I should require a properly appointed party of three or four men, with tents, tools, a Californian pump, and a pack horse, with a good foreman, while if the search for gold should be left to private enterprize, a smaller party would suffice for the detailed survey.
Such an undertaking as the bottoming of the Wairarapa valley would necessarily require special consideration and authorization, for although a small sum might suffice for the work, yet unforeseen difficulties in depth and in the influx of water might arise.
In my letter of December 13th, 1862, I mentioned the discovery of the plant bed series of the Porirua harbor. Since that time I have discovered similar organisms in different directions—at Ohariu, on the banks of the Aka-tarewa, and on the Belmont line, and Mr. Mantell has even found them at the top of the Kai-warra-warra road. As Professor McCoy has decided these rocks to be carboniferous, of the oolitic age, I would fain hope that workable seams of coal will be found, and although appearances are not very encouraging, yet, after having seen the manner in which the Kowhai coal seams at Canterbury were hidden by drift, it will be a long time before I shall despair of success.
The traverse and survey of the rocks which I propose to make from the West coast to the Wairarapa by the line of road, would be a necessary preliminary to the search for coal.
I Lave discovered a black mineral at various points on the Rimutaka, hill, but its character is not yet determined.
For political reasons, it would probably be best that deep sinking should be tried in the Wairarapa, before attempting it on the west coast.
Mr. Brough Smyth will perceive why more attention has been paid to the discovery of quartz veins than of alluvial or drift diggings. The mass of drift having been thrown out of the mountains upon the adjacent plans or basins, rather than deposited within their own area, in a position which often renders it difficult to tell its thickness, or what rocks may lie between it and the undulation of the ancient rocks, I required some support to back my opinion in favour of deep sinking in the plains or basins. You will also observe that the country covered by horizontal tertiary formations can, for all present purposes, be disposed of geologically with great rapidity, while the inclined rocks of the main range require
a most patient and searching investigation.
I have proved the “gold constants,” and I have obtained strong evidence in favour of the probability of finding gold. But should the “gold constants” prove inconstant, and the precious metal elude our search, there is no reason to despair of making discoveries of other valuable metals. I have every reason to think that these ranges are full of mineral veins, and at the present moment I await reports on the character of those already found; but at the same time, I suspect that our mineral wealth lies deep, and will require an expenditure of skill, capital, and patience for its developement.
I have the honour to be
Sir.Your most obedient Servant,James Crawford,
Government Geologist.
[Enclosure.]
Mr. R. Brough Smyth's Notes on the specimens of rocks collected in the Province of Wellington by the Honorable J. Coutts Crawford.
Melbourne, January 13th, 1863.
I have carefully examined the specimens of rocks brought from Wellington by the Honorable G. S. Evans. I have also read the printed reports of excursions made by Mr. Crowford in that Province, and the MSS. accompanying the specimens.
I have had some difficulty in fixing the several localities (not being provided with a good map) and I have not been able to gather any information relative to the extent of the areas occupied by the several rock formations. Under these circumstauces it is necessary to speak cautiously and to draw conclusions only when the evidence is clear.
Amongst the more important specimens of rock submitted, I recognise mudstones, similar in lithological character to the rocks occurring in the basin of the river Yarra, greyish blue mudstones with iron-pyrites and thin veins of alumite containing more or less silica, and quartz.
I also observe a very fine grained granite rook, and a rock, evidently derived wholly from the degradation of this, consisting of quartz, felspar and mica, with included pebbles of quartz.
Much of the granite rock contains veins of quartz.
Judging from the specimens submitted, it would appear that part of the valley of the Upper Hutt is occupied by plutonic rocks, but how far these extend, or whether the quartz veins intersecting the primary rocks also run into the granite, it is impossible at present to say.
In Mr. Crawford's report, dated the 24th October, 1861, it is stated that the metamorphic rocks fill a large area and compose the Rimutaka and Tararua ranges, but I do not recognise amongst the specimens any gneis, clay slates, or mica schists.
I regret that Dr. Evans' hurried visit did not admit of Mr. Crawford's giving more information respecting the quartz veins of the Province. I observe specimens of ferruginous quartz, milky quartz, and much chalcedonic quartz, but how the veins occur, or whether they are thick or thin is not stated, without this information it is impossible to give any useful opinion respecting them; for hand specimens may be obtained abundantly where the veins are thin, and, comparatively, few and unimportant.
One very interesting specimen of basalt, with glassy crystals of felspar, a fragment of a boulder from the bed of the Hutt, would indicate that igneous as well as plutonic rocks may be looked for in that part of the basin.
A fragment of a purple slate rock, marked “Hawtrey, Johusonville” appears to me to be important in connexion with the specimen of quartz No. 11, from the same locality.
All the rocks, including the quartz and excepting the granites and conglomerates contain more or less iron pyrites, and the specimens taken from Barraud's well, which contain alumite, resemble very much the mudstones of the Heathcote District, where we find gold, sulphide of antimony, chrome iron, and a mineral resembling bournonite.
I submitted the fragment of sandstone marked No. 37, to Professor McCoy, He at once prouounced it as of mezozoic age, and similar to the coal formation of Meruio in Victoria.
The other specimens are devoid of fossils, but the mudstones may, I think, be safely set down as palæozoic.
With but imperfect means of coming to a conclusion, it may be said that the rock formations of the Province of Wellington comprize
Recent accumulations.
Tertiaries, age unknown.
Carboniferous rocks of the oolitic age.
Mudstones, probably Silurian.
Granites and other plutonic rocks.
As the discovery of gold in remunerative quantities would no doubt have a most beneficial influence on the future prospects of the Province, I would recommend that the recent drifts should be carefully examined. Attention seems to have been directed rather to the quartz reefs than to these but it must not be forgotten that elsewhere gold occurs in drifts and in Post Pliocene accumulations in quite sufficient quantities to pay for working, in the midst of primary rocks in which there are but very thin and apparently unimportant veins of quartz, the exploration of which would never reward the enterprize of the quartz miner.
If the suite of specimens forwarded by Mr. Crawford fairly represent the rock formations of the Province it may safely be asserted that the search for gold may be prosecuted with every prospect of success. I have not yet had time to analyse any of the specimens, or indeed to apply any but the slightest chemical tests to one or two, and therefore I cannot say whether or not they contain gold, except as regard the fragments of rock and clay taken from Barraud's well. In these I detected a very small grain of gold.
Whether the gold found in the well is derived from small veins of quartz penetrating the mud stones, or whether there is a thin surface stratum overlying the older rocks which is auriferous, is well worth investigating, and I would recommend that the locality should be carefully examined. What is the prevailing rock in this neighbourhood? and has it been ascertained whether or not the surface soil is auriferous? Is there any reason to believe that gold dust has accidentally fallen into the well and become mixed with the debris there? These questions would be answered by a not very laborious investigation.
Wherever we meet with silurian (or older) rocks intersected by veins of quartz, we may look with confidence for the discovery of metaliferous and mineral veins of more or less importance. It appears that we have all the conditions in the Province of Wellington. If I were to submit many of the rocks collected by Mr. Crawford to any gold miner in Victoria, he would recognise them at once as precisely similar to those occurring on some of the Victorian gold fields; and while a few specimens of the milky and ferruginious quartz are quite like our own, the chalcedonic quartz exactly resembles that found in the Northern gold fields of New South Wales. Without attaching too much importance to these resemblances (for quartz veins are not always auriferous) they yet serve to show the necessity for earnest and careful exploration of the country.
Looking to the physical geography of the North Island of New Zealand, one observes a main chain of mountains, running generally in a Northerly direction with Easterly and Westerly spurs of considerable extent. The position of this main chain (broken as the other lands may be) has determined the course of the principal river basins, the more important of which lie on the West side of the main range, If a geological map were constructed of this country it would not probably differ, in its main features, from many parts of Eastern Australia. We should find, I apprehend, the central axis composed of rocks of the primary age, with masses of intrusive granite, and many of the spurs of basalts and lavas of different ages. We should also find areas occupied by carboniferous rocks, and large tracts covered by tertiaries of greater or lesser thickness.
Though the information I have received is not very complete, it would appear that on the Eastern sea board rather thick tertiaries prevail (probably of the same age as the Murray tertiaries) and I would therefore recommend that the rivers flowing to the Westward should be first explored. There, I am led to believe, the quite recent accumulations of drift, similar to these occurring on our Victorian gold fields, are prevalent, and no very costly examinations would be required to ascertain whether or not these recent accumulations contain gold, or tin ore, or the ores of other metals, in remunerative quantities. There is no reason to believe that gold is more likely to occur on the Western side of the main chain than on the Eastern. But it is probable, owing to the local distribution of the rocks, that it will be found more easily on the Western side. The rivers in Victor'a on the Eastern side are all auriferous.
I would suggest as particularly worthy of immediate attention the basins of the Hutt, the Waikanae, the Otaki, the Manawatu, the Rangitikei, and the Whanganui.
Unless careful attention be directed to the conditions under which gold occurs, a long period may elapse before any important discoveries are made in this part of New Zealand. Looking alone to the modes of occurrence of gold in Victoria, people in other countries may utterly neglect the most important localities,
because the conditions there are not the same as there. In Victoria we find the silurian and metamorphic rocks every where intersected by veins of quartz, varying in thickness from a line to fifty feet. These quartz veins, nowhere, it is believed, penetrate the great masses of plutonic rocks which every where have broken through the sedimentary strata. They stop short at the granite boundaries, and the gold miner, accordingly, as a general role, neglects the granite country. This peculiarity is due probably to the relative ages of the granites and the sedimentary rocks. The force which rent asunder and left wide fissures in the clay slate and schist formation was perhaps exerted before the granites came to occupy their present place, or perhaps the force was insufficient, or exerted so as not to affect the denser, tougher and harder plutonic rocks. It is a local peculiarity, not a condition universally occurring. Elsewhere gold is found in granite, in gneiss, in mica schist, in syenitic porphyry, in green stone, as well as in quartz veins intersecting rocks of the silurian age.
It may be looked for, and yet may be profitably worked in conglomerates much older than tertiaries.
Gold is found in quite modern drifts overlying granite rocks—not derived from auriferous quartz veins penetrating the granite but from veins in slate rocks which have wholly disappeared. The slate rocks have been denuded and their rich stores of gold have been left in holes and “pockets” of the granite, the bed on which the slate rocks were originally reposing. A granite country therefore (more especially if in the neighbourhood of schists) should not be neglected, but explored carefully and anxiously. The gold said to have been found in Greaves' Gulley, may have been derived from auriferous veins penetrating sedimentary rocks, or it may have been derived directly from veins intersecting the granite.
If I might venture to offer a suggestion, I would say that instead of a hurried examination of a great extent of country, it would be more satisfactory to make a careful examination of a comparatively small area,—say the basin of the Hutt, the Otaki, or the Manawatu. I would recommend that the upper and lateral branches of these rivers (at some distance from the coast) should be carefully explored, and rough sketch maps made showing the various rock formations,—rough maps which might hereafter be amended, revised, and in some parts wholly altered as discoveries would from time to time, be made. The recent drifts filling the valleys of the small tributaries, should be carefully examined down to the bed rock, and the whole depth of each section washed very carefully. One or two careful examinations of this kind would in fact be the very best kind of “Prospecting.” I would suggest just such examinations as Mr. Stutchbury made in New South Wales, and exactly such maps as he constructed.
I do not think explorations very near the coast will be productive of useful results. If we look to the rivers in Victoria we gather some useful hints for the gold prospector. Near the coast the sands of these rivers are almost invariably so poor in gold that they may be said practically to be non-auriferous For many miles the Yarrowee is non-auriferous, and quite at its sources we have the Ballaarat Gold Field. The Coliban and Campaspe flow into the Murray through a pastoral country, but their tributaries, miles away from their embouchures, are now supporting large numbers of gold miners. The Loddon is only auriferous near its sources, and the same may be said of the Hopkins, the Wimmera, the Werribee, and every river in the country. A very slight consideration of the facts counected with the occurrence of gold in drifts and recent accumulations will show that the sources of streams, rather than the streams themselves, are most likely to yield the metal in remunerative quantities.
It is probably true that gold is widely disseminated in rocks of the oolitic age, but, according to our present knowledge in such a state of minute subdivision as to be wholly unavailable to the miner. The sludge from a puddling machine contains gold, but the greatest quantity is caught and retained in the box. And so we may consider this operation of nature by which great masses of rock have been worn down and washed as but another kind of puddling, and we must reach the source of that grand agency before we find the gold.
I have not alluded to the modifications likely to be produced in the strata of the drifts and recent tertiaries by glacial action. These should not be overlooked by the gold prospector. Where this force has been exerted gold may be distributed very unequally through the strata, and such rocks may quite puzzle even the experienced gold miner. Though it is true that the specific gravity of gold is sufficient under ordinary circumstances to determine its position on the surface
of the bed rock, yet when the gold is imbedded in large fragments of quartz it may be found at all depths from the surface downwards, and in conducting explorations in drifts of this kind all the debris should be carefully examined.
As there are undoubtedly coal bearing rooks in the Province of Wellington no opportunity should be lost of shewing the extent, thickness, dip and general character of these.
R. Brough Smyth.
Wellington, April 13, 1863.
To His HonorI. E. Featherston.
Superintendent of the Province ofWellington.Sir,—
As favorable reports upon our rocks rendered it desirable to ascertain whether alluvial or drift gold was to be found within the limits of the ranges on the northward of this City, or in drift derived from them, I organized a pros-pecting party which started for the Upper Hutt on the 27th of February last. My plan was to examine the different river basins within the ranges, and should gold, even in small quantities, be found in them, to bottom the plains, or basins, lying outside the ranges on both sides.
I looked upon the Hutt Valley, however, as almost a decisive test, for it is the great valley of Tararua, and should no gold be found in it, felt little expectation of finding it elsewhere in these districts. We proceeded to sink a hole in a gully behind Mr. Brown's house, in the Upper Hutt, where some small scales of gold were previously reported to have been found. This hole was sunk through clay and debris, bottoming on fine grained granite at a depth of eleven feet, without finding the “colour” of gold. In this hole, as in every other which we sunk, we obtained a small quantity of iron sand. I may as well here state that the fine grained granite of the district does not appear to me to be an intrusive rock. The slates and mudstones in its vicinity do not seem to be altered, and I therefore assume it to be older than these sedimentary rocks. As some incredibility has been expressed as to its being a true granite I will give the opinion of the Rev. W. B. Clarke, which, in addition to that of Mr. Brough Smyth, will I suppose be considered conclusive. Mr. Clarke writes as follows:—“It is clearly not a mechani-“cal rock, It contains three constituents, “felspar, quartz, and white silvery un-“worn mica. It has a trace of horn-“blende, and in its original state was “jointed, with segregations of quartz “along the joints, in threadlike veins, “with points of mica prominent. The “proportion of felspar to the quartz is “not less than 2: 1 and in parts 3: 1. “It is therefore a granite rock to all in-“tents and purposes and never was a “sandstone.”
Our next endeavour was to bottom the gravel flats of the Upper Hutt in several places, but from the influx of water we found this to be impracticable; the river evidently percolates through the gravel right across the valley and the quantity of water was quite beyond the power of ordinary pumps. As however the bed rock of slate, &c., crops out in many places above this, both in the bed and on the banks of the Hutt, we were enabled to try the gravel when it rests upon the old rocks, but still without success.
We devoted a day to to the bills above the Mungaroa swamp, a locality which I thought extremely unlikely for gold, there being neither drift nor alluvium, but in deference to the wishes of the inhabitants we gave it a trial. We next examined the valley of the Pakuratahi and the gullies in the neighbourhood of Featherston, but without success.
As the valley of the Tauherenikau was so close that a change in the rocks was unlikely, we passed it and proceeded to the Waiohine, which we prospected and washed at every available place for a distance of six or seven miles from the entrance of the Gorge. As in the Hutt, it is impossible to bottom the gravel bed of any of these streams below the water level, but there is plenty of bed rock above the water level, with thick beds of drift resting on it. No appearance of gold was found. The rocks were similar to those found on the Rimutaka hill, including large quantities of soft pyritous slates with lime veins and veins of black mineral, apparently an iron ore Boulders of amygdaloidal trap were found here, and also in the stream behind Featherston. As the Waingawa had been lately examined by Mr. Thos. Kempton, and the rocks he described were precisely similar to those found in the Waiohine, I passed over that river and also the Waipoa, which latter does not appear to penetrate far into the range, and proceeded to the gorge of the Ruamahunga. Here, at the head of the open country, we found an unoccupied house belonging to Mr. Skipper, which we took the liberty
of making our head quarters, and which I found was at a height of 987 feet above the sea. Here the formation is drift gravel, resting upon the blue clay, and in the river bed below may be seen the point of junction, where these tertiaries abut on the old and highly inclined rocks. The rise from Masterton to this point is tolerably rapid, and on the Opaki plain, and the adjoining hills, are very palpable marks of the earthquake of 1855 and perhaps of other shocks; at one point there being a lift in the plain of perhaps 30 feet and a tertiary hill having been split in two and the Western part slipped down towards the river bed. Between Mr. Dorset's, on the Opaki plain, and Masterton, there are said to be seven terraces; and from Mr. Dorset's to the head of the Pairau plain at the gorge of the Ruamahunga there are many more. At the upper part of the valley the Ruamahunga is difficult of approach, from the steepness of its banks, but below Mr. Skipper's is the Maori path which leads to the forty mile bush, and by which the river bed can be reached. The upper part of the valley forms a very pretty amphitheatre; and we found the woods full of pigeons and kakas.
On the day following our arrival we were detained by heavy rain and the next day the river was in full flood, however we made our preparations to start on the day after, taking four days provisions, with the intention, after prospecting the river for gold, of making our way to the bare ridges of Tararua, which appeared to be only a few miles from us.
Our search for gold met with the same negative results as in the other valleys and we found the same series of rocks, and the same iron veins as in the Waiohine. These latter were, however, in great abundance, and at one point appeared to be largely developed, where however deep water under an inaccces-sible cliff rendered a close examination impossible.
There is an appearance of a valley of some extent within the hills, but the bush is so dense that I will not venture to guess at the extent of terrace land which may be there. It lies, however, at a height of over 1000 feet above the sea. After rather stiff wading up the river for about six miles, we found the water become so deep from the compression of the bed of the river between perpendicular cliffs, about 150 feet high, that we were obliged to abandon the river bed and take to the forest above. We had by this time given up all hopes of finding gold, and were on the look out for a point from whence to ascend the central range; when, after we had proceeded for a mile or two through the bush, the weather suddenly changed and it soon rained so hard as to force as to a precipitate retreat. We succeeded in getting to camp just in time before the river rose and the following day it was in full flood. My experience of the Ruamahunga was this, that one day's rain raised the river, on the following day it was in full flood, on the third day the stream was fit to travel and on the fourth day it began to rain again.
Jasper and a green serpentinous rock are characteristic of the Ruamahunga. There is not much appearance of quartz. To a person desirous of reaching the top of the central range, the valley of the Ruamahunga offers the advantage of starting from an elevation of over 700 feet above the sea before leaving the open plains and the distance to the open country above the forest is comparatively small.
As the weather continued very changeable and no gold had been found, I did not consider it advisable to continue the expense of the whole party of men who were with me. I therefore discharged and sent back all but two hands, with whom and a Maori guide I started on the the 24th March, to pass through the forty mile bush. Our road descended to the Ruamahunga by the Maori track, crossed the river, ascended a terrace and then passed over a hill called Kotukutuku of no great altitude. This hill, however, I believe may be avoided altogether, by taking the line of road lower down on the Ruamahunga. In three hours we reached the Maungawhinau stream, said by our guide, Hemi Paraone te Ma, to be a tributary of the Ruamahunga, but my impression is that he is wrong, and that it runs towards the Manawatu basin. The road frequently crosses this stream, a disadvantage which might probably be easily obviated. After crossing the before described hill, the road was nearly level except an occasional ascent of a terrace bank. We encamped on the banks of the Makakahi, on an undoubted northern fall. It is a rapid stream, much encumbered with drift wood. My horse lost both hind shoes this day, and nearly disabled his off fore leg, getting entang'ed in a root, and plunging furiously before I had time to hold his head down. There was no food for him either except leaves. The line of road for horses however would soon be good, if every traveller carried a billhook,
and if a little labour were expended upon removing logs lying across the road, and cutting down the banks of the small streams at the crossing places.
On the 25th of March we passed over level ground covered by tawa and pines, until after five hours travelling we came to what our guide called a hill. There was a slight ascent and then a descent for about 180 feet.
From the dense character of the bush I cannot speak positively, but it appeared to me that we were rather descending from a terrace than going over a hill. However that may be, there are no more hills between this point and the Manawatu river east of the gorge. Heavy rain coming on we were glad to find a maori shed and potatoe garden on the banks of the Maungatainoko and plenty of sow thistle and koromiko for my horse; it being the first feed he had had, except leaves, for two days.
The Maungatainoko is here a stream, perhaps more than half the size of the Hutt, gravel derived from Tararua On the 26th of March after two hours level travelling we again crossed the Maungatainoko, obtaining a view Tararua covered with snow, the forest consisting of rimu, tawa, totara, &c. On the banks of all the large rivers, the Makakahi, the Maungatainoko, and the Maungawha, there is plenty of feed for horses, but the small streams are wooded to their banks. Soon after crossing the river we came to the Hawera flat, an open space in the forest, and undoubtedly an old maori clearing, as apple trees were growing in it. As it took us only twelve minutes to walk across its largest diameter, the area is not great—gravel terraces bound this clearing on the eastward. At 2 p.m. we reached the pa Tutaekara, situated on an open flat of about 200 acres, on the banks of the Maungatainoko, and inhabited by a population of about a dozen maories, mostly old men and women, under a chief called Mikara; they were suffering dread-fully from influenza. I believe Tutaekara, or some place in its vicinity, will eventually be a point of importance, as the intersection of the road from the East Coast, with the trunk line to Napier, will probably strike hereabouts. An intelligent young Maori informed me that he had just arrived from Knight's station, which he described as seven miles distant. He had cut his way through the bush in two days; the road level, with three rivers to cross. The Tiraumea, the Ihiurawa, ane the Maungatainoko. From the bearings which I afterwards obtained his distances must be very nearly correct. He gave East as the bearing of Knight's station. The Puketoe range he estimated at five miles distant to the Eastward and the nearest ranges of the Tararua appearing to be at least five miles distant to the Westward, would give a breadth to the valley of the forty mile bush of about ten miles.
From Tutaekara the pass of Tararua bore 30° W., a bald ridge of Tararua 80° W. Ruahine, North.
In the pa there was a tame huia, a bird in much request among the natives and much sought for in the Puketoe range. On March 27th, we started with a fresh guide, Hemi Paraone complaining of sore feet. We made a bad exchange, as our new man, Patorimo, was very lazy. Our road now trended to the westward and towards the foot of the ranges. At noon we ascended a terrace and looked down on the valley of the Maungawha, where that river makes some great bends through cliffs of blue clay and gravel and a fine view is obtained of Tararua, and of one of its ridges called Tirohanga. We encamped at a place called Uki-uki, on the banks of the Maungawha, a very poor day's journey. Here the river, the soil and the forest put me in mind of the Hutt Valley before it was cleared. A good deal of tobacco was growing here, and we found both here and elsewhere that, stimulated by high prices, or for other reasons, the cultivation of tobacco is becoming extensive among the Maories. Although the quality is said to be inferior with their modes of preparation, may it not be worth while to try if improved methods will not produce a good marketable article? The plant itself grows luxuriantly, I observed that the young plants were shrivelled by a hard frost of the previous night, but the full grown plants did not seem to be in the least affected by it.
On March 28th, we travelled for three hours and a quarter, over a nearly level country, when we reached the Ka-uki stream immediately below the main range, at the point of junction of the horizontal, or nearly horizontal, tertiary, and the highly inclined old rocks; and now that we have again reached the old rocks, it will be advisable to describe the geology of the Forty Mile Bush. This appears to be merely a continuation of the geological formations of the Wairarapa. Although large distances are traversed where the rocks are hidden by vegetation, yet, where-ever visible, they are tertiary. I found tertiary sandstone in a stream near the
Makakahi—the terraces are generally composed of tertiary drift gravel—tertiary blue clay and drift gravel forms the cliffs of the Maungawha, and in the Ka-uki stream, I found the banks composed of an indurated fossiliferous clay, probably the blue clay, although the fossils were too indistinct to make sure. Further investigation, to connect the Rua Taniwha plains, will probably shew that a Sound, or at all events arms of the sea, have swept through these districts, removing by denundation the tertiary sandstone, which is so largely developed in this district and the East Coast. The gravel of the rivers in the Forty Mile Bush is the usual gravel of Tararua, its characteristics being similar to that of the Ruamahunga, showing a good deal of jasper and a green rock, (both probably connected with igneous veins), and very little quartz. In the Maungawha I found some very coarse liguite, exactly resembling that found on the banks of the Manawatu below the gorge. In the Ka-uki stream I found a boulder of crystalline limestone. Travellers must be careful in looking for the track in the Ka-uki stream as the descent and ascent are very steep. The Forty Mile Bush may be concisely described as a district of gravel terraces and alluvial flats.
Starting from the Ka-uki sueam we ascended and crossed the main range of the end of Tararua (whatever may be its name hereabouts) on one ridge only, that is to say we had no valleys to cross. Our progress was slow, as we wad to cut round a number of fallen trees, but we reached the level land on the West side (at the same elevation exactly as the Ka-uki stream) in three hours and three quarters, having passed over an elevation of only 915 feet above the level land on both sides. In another hour we arrived at Raukaua on the Manawatu.
From the hill which we had just crossed a better notion of the resources of the Province can be obtained than from any point which I could mention. To the eastward the view extends over the rich plains of the forty mile bush to the Puketoe range, down the spurs of which the main stream of the Manawatu is seen to wind, until it reaches the plain through which it meanders Westward to the Gorge. The Puketoe appears wooded to its summit, but on its Northern shoulder open country is visible stretching to the Eastward. The view to the Southward shows beyond the Forty Mile Bush, the bills beyond Masterton, and in fact the whole landscape from the Tararua almost to the East Coast, while to the North Eastward the forty, now we may say the seventy mile bush, continues as a valley or plain, as far as the eye can reach, bounded by the Ruahine on one side and by the broken hilly country on the other.
Crossing the range to the Westward, a view is obtained of the extensive plains of the West Coast. Altogether I doubt if there is any part of New Zealand which has equal ultimate resources, in soil, climate, and eventual communication with a market.
The sandst sones which I found on the main range are precisely similar to those near Wellington. Semi-crystalline sandstones, soft sandstones, and felspalthic sandstones. The pass over the range is apparently about three miles south of the gorge.
From Raukaua we descended the Manawatu Valley by land, having in some places to cut our way through the bush. The road as far as Puketotara passed through rich alluvium, the higher gravel terraces appearing occasionally on both sides. We found a strong party of natives cutting a track through the bush, intended, they informed us, to allow stock to be driven through from Heretaunga or Hawke's Bay. The mouth of the Oroua at Puketotara seems to mark the line of demarcation between the rich land of the interior plains, and the poorer sand tracts towards the coast, and as the aneroid marked exactly the same height at Puketotara as at Te Awahou, I would venture to suggest that the principal township of the Manawatu, ought perhaps to be at, or near Puketotara, and the river navigation improved up to that point, in which case the main trunk line of road from Wellington to the North, would pass through and open fertile lands instead of traversing sand hills.
From the Manawatu we proceeded to Otaki, and having laid in provisions and obtained the services of Manahi the Ferryman as a guide, we proceeded up the river.
I was rather surprised at the breadth of fertile land between Otaki and the hills. It took us two hours hard walking (with packs) to reach the Wairarapa pa, and then we had not reached the hills. At the Wairarapa pa the ascent of the river was discussed by the Maories, and it was settled that a deputation of two was to accompany us to see that we did not carry away too much gold.
The valley of the Otaki river is remarkably similar to those of the Waio-
nineWaionine and Ruamahunga, but it is less wild and the cliffs are not so high. The river winds between cliffs about 70 feet high, composed of highly inclined slates, sandstones, &c., capped by drift gravel terraces, the latter formation of various thicknesses, from 6 to 30 feet. Mamako and other tree ferns abound. The stream is rapid and quite deep enough for wading, indeed it was sometimes difficult to keep one's feet. As we approached the central range the Waitatapia was passed, falling into the right bank. Up this stream lies the road to the Ohau river. A short distance higher up, and we may say at the base of the central range, the Otaki divides into two branches, that from the Northward retaining the name of the Otaki, while the Southern branch is called the Waiotaueru. The Northern branch is said to be full of deep holes and very inaccessible, we ascended the Waiotaueru for some miles and encamped near where a stream falls into the right bank.
We were now in the midst of soft vertical slate rocks, which had been described to me as full of quartz veins, but the said quartz veins turned out to be lime. The same pyritous slates with lime veins which I had found in tho Wairarapa rivers and elsewhere, here very largely developed. In the neighbourhood I found the black mineral found elsewhere, but no metal except iron pyrites is visible in the lime veins themselves. The specimens from them however will require careful investigation. One curious feature is that in the more siliceous vein stones or nodules (for they are aften nodular)* thin veins of lime traverse them crosswise, or at right angles to the strike of the vein.
The sequence of the rocks from the entrance of the gorge may be taken roughly as follows.
Sandstones—probably mezozoic Apparent strike East and Wes Dip North 70° to 80°. (I am not quite satisfied as to the East and West strike Some of the rocks certainly had that strike while others were doubtful.
Soft slates with lime veins—strike apparently North by South.
Fine grained granite (say 200 yards.
Felspatho siliceous rocks, slates mudstones, semicrystalline, sandstone and black mineral veins.
At junction of Waiotaueru soft slates with lime veins and semi-crystalline sandstone with quartz veins.
To highest on Waiotaueru. Almost altogether soft slates with lime veins vertical, with a North and South strike, black mineral veins adjoining a sandstone.
Topridge of Tararua—sandstones. We had washed the river for gold at every available point, but without success. At our camp on the Waiotaueru we were detained for a day by heavy rain, but on the morning of April 8th we started up the mountain, taking the line of a spur near our camp. The ascent is very much like the usual bush travelling in this neighbourhood. A great deal of kareau near the bottom, and altogether a very steep road.
Our guide, Manahi, had ascended to a certain distance last summer, by himself, an extremely brave thing for a Maori to do, but frightened by a storm of wind and rain, he had retreated, thinking that the Taniwha was angry. I propose to call this ridge Manahi's pass, after as pleasant and obliging a Maori as I ever travelled with. It lies between the North branch of the Otaki and the stream which falls into the right bank of the Waiotaueru near which we encamped. Manahi also aspires to the post of guide to the Maunga huka, snowy ranges, for which he is well qualified.
We soon looked down upon the range above Waikanae, which I find the natives call Rimutaka, so that name is not confined to the range adjoining the Southern part of Wairarapa. It now appeared to me that only one ridge separates the Waiotaueru from the Akatarewa and that by turning to the right in the ascent of the latter river, and crossing one range the Waiotaueru would be reached with ease. After about five hours climbing we found the trees become Alpine in character and covered with moss, and in five and a half hours we emerged from the forest upon the open ridges above at a height of about 3000 feet above the sea. The Alpine trees were mostly totaro and black birch. The vegetation above the forest shrubs of veronica, tarata, a sort of broom, moss, flax, toi and a little grass.
Here we were surrounded by snowy ridges and commanded a most extensive view. The Kai Koras were extremely distinct, and also the Bluff, and the land about Cape Campbell, with that part of Cook's Strait lying between the latter and the land about Wellington. The
mountains surrounding us were broken into long and very steep ridges, separated by ravines some two thousand feet deep, all forest except the line over 3000 feet which is open, but in which bushes are found often as difficult to pass through, as the bush.
There was no appearance of any level land within the mountains.
We looked down upon the Ohau valley, a deep ravine, but the view towards the far N.W. was shut out.
The paps of Tararua appeared certainly to be on the same ridge on which we stood and I should have liked to have gone on to them and looked down upon Greytown, but we must in that case have remained all night upon the mountain we had neither food, nor blankets, and the exertion was too great to go on without the former. Manahi had promised to take us to the top of the mountain and back again in the day, and as I thought that this meant that we should probably reach the paps, we had started in light marching order, otherwise, from the steepness of the bill, our progress must have been much slower.
I think the ascent from the river and from the ridge to the paps might be done during one long summer's day and now that there is a marked track through the bush, the journey up the river and mountain may become a pleasant summer excursion, which would be rendered more agreeable by a little work in cutting away the kareaus; but I am convinced that the paps are not the highest point of Tararau but that the summit ridge lies some eight or ten miles further North, nearly opposite Horowhenua. Manahi knew nothing of a reported lake in this direction, nor could we see any appearance of one. The central ranges are called by the natives Maunga huka, sugar or snowy mountains.
At the edge of the forest we found a good many plants of toi, which plant, Manahi informs me, is in great request among the maories, possessing a fibre stronger, more lasting, and much more waterproof, than flax. He says that in districts where it is not found the natives will give ten shillings and more, for a single plant. This information is worth testing.
The plant must be very hardy for I have never seen it growing except at greats heights, it is plentiful upon the Rimutaka hill. I have never seen it in flower or seed, perhaps, like the aloe, it may only flower at long intervals. Its root is said to be good eating and the plant is very graceful and would be an ornament in our gardens.
The natives found a feather on the mountain, which they said was that of a kakapo, but the learned in these matters tell me that it belonged to a pigeon.
We descended to the camp in three hours, having found no water since we left the river in the morning.
The temperature had fallen very considerably within the last few days and the nights were cold, when we started therefore from our camp on the Waiotaueru, on our return on the morning of April 9th, we found the water extremely chilly, and therefore pushed on as fast as we could. The current of the river is so strong that it keeps the small gravel in constant movement, and consequently fills one's boots with sand and pebbles, which does not add to the pleasure of travelling. After nine hours walking, seven of which was almost constant wading, we reached Otaki, performing downwards in one day, a distance which took more than two days in the ascent. It was lucky that we did not remain on the mountains, for that day they were covered with dense clouds and the river showed signs of rising before we left its bed.
At Otaki I was shown a good specimen of quarts from the Ohau river, but hand specimens may be got in many places. The rocks of the Ohau are pretty sure to be similar to those of the Otaki from the dip and strike of the latter. I did not consider it worth while to examine the Ohau at present for several reasons amongst others because it would probably have led to an altercation with the king natives who are residents there, and because the water is now too cold for wading explorations.
On my way to Wellington I made some enquiries at Waikanae as to the coal reported to be found on Kapiti, and from the description given it appears to be black slate.
I subjoin the following heights, taken with the pocket aneroid. As the instrument has no attached Thermometer, I must again remark that the heights must not be taken as strictly correct.
LocalityHeight above sea.Brown's Hotel, Upper Hutt164 Feet.Mungaroa Bridge248 Feet.Mungaroa Hill774 Feet.Pakuratahi Bridge552 Feet.Top of saddle, Rimutaka Road1636 Feet.mean of three observations
Wairarapa.
Featherstòn143 feet.Greytown and the same143 feet.Waiohine BridgeChalmers (Potsdam)262 feet.Ray's (Carterton)236 feet.Donald's, Manaia, (mean of three observations367 feet.Masterton, (mean of four observations)322 feet.Dorsett's (Opaki Plain)495 feet.Campbell's (Pairau Plain)632 feet.Skipper's (Gorge of Ruamahunga)987 feet.Bed of Ruamahunga below Skipper's771 feet.Highest point reached on Ruamahunga1234 feet.
Forty Mile Bush.
Mangawhina stream, (Forty Mile Bush)947 feet.Camp on Makakahi River837 feet.Top of hill or terrace beyond Makakahi River866 feet.Bottom of hill terrace679 feet.Camp on Mangatainoko459 feet.Tutaekara351 feet.Uki Uki pa (on Maungawha)420 feet.Uki Uki stream at foot of main range486 feet.Top of main range (say three miles South of Manawatu river)1402 feet.Bottom of main range (West side)486 feet.Raukaua320 feet.
Puketotara and Te Awahou show no perceptible height above the sea level, except of course the river bank.
On Otaki River.
Wairarapa pa24 feet.Koaraitea (granite locality)104 feet.Junction of Otaki and Waiotaueru304 feet.Camp on Waiotaueru457 feet.Highest on upper ridges of Tararua3047 feet.
On comparing the results of my aneroid with measured heights, I regret to say that there appears to be considerable error, and the ratio of error seems to increase with the height, my heights are under the mark.
I regret the negative results of the expedition as far as gold is concerned, but you may be satisfied that no exertion was spared to find that metal. Mr. Cook, who accompanied me, is a most careful prospector and skilful washer, and with regard to other metals Mr. Thomas, of the Hutt, who was also of the party as far as the Ruamahunga, will not readily let a mineral vein escape his observation.
I have the honor to be,Sir,Your Obedient Servant,James C. Crawford,
Provincial Geologist.
Wellington, April 14, 1863.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
I have the honor to submit the following report of the results of the geological observations made by me in this province during the past and present year.
The characteristic features of this province is the immense area covered by sedimentary tertiary rocks, comprising perhaps eight or nine tenths of the whole.
The older rocks form the mountain chains of Rimutaka, Tararua and Ruahine, the Aorangi range at Cape Palliser, the Kaimanawa range and the islands of Kapiti and Mana, while the sedimentary tertiary rocks occupy all the rest of the Province, with the exception of the igneous tertiary and recent rocks of the volcanic chain of Ruapehu and Tongariro, I must also for the present exclude the limestones and calcareous grits of the East Coast (age still undetermined), although I believe them to be tertiaries also.
I need not again repeat the sequence of the tertiary rocks.
You will bear in mind that there are two lines of dislocation and upheaval traversing the whole length of the Province,
The main ranges of Rimutaka, Tararua and Ruahine, on a line of about N.N.E. true.
A line of fracture and upheaval, nearly parallel to the East Coast and distant about eight or ten miles from it. On a line of about N.N.E. magnetic.
There are also two lines to the Westward but which only advance a short distance into this Province.
The Kaimanawa range, parallel to Ruahine.
The volcanic chain of Ruapehu and Tongariro.
These may be said to form the ribs of the Province, while the tertiaries fill in all the rest.
In the tertiary rocks no metals can be expected, although limestones and brown coal may be found in workable quantities.
Although tertiary rocks are deficient in minerals, yet as a general rule I think they may be said to support the densest agricultural populations, and some of the principal cities of the world have been built upon them. I may instance London, Paris, Rome. It is probable that the same rule will hold good here, and that the tertiary rocks of this Province, where comparatively undisturbed will on
both the Eastern and Western sides of the range, but particularly on the latter, give employment to a numerous people. In fact it is only by labour that the resources of these districts can be developed.
Whanganui may be said to be the centre of the tertiary rocks of the West Coast, Napier of those of the Eastern sea board, while the City of Wellington is planted in the midst of the ancient rocks on which these tertiaries abut.
Having determined the great mass of the Province to be of tertiary age and therefore devoid of minerals, the search for these latter was consequently restricted to the ancient rocks of the ranges above named.
In consequence of the favorable opinion formed from an inspection of the rocks of these ranges, of our chances of finding gold, I have lately made an investigation of the various river beds of the Rimutaka and Tararua, and regret to say without finding the “colour” of gold in any of these streams, comprising the valleys near Featherston, the rivers Waiohine and Ruamahunga the Makakahi, the Maungatai noko, the Maungawha, the Uki-uki, the Manawatu and the Otaki.
I have been kindly favoured by the Geological Department at Otago, with a sections of the sinkings at Tuapeka, showing the existence of an old gold drift below some tertiary sandstones and beds of coal. Had we found the colour of gold in any of the streams above named, I should have strongly advised what I have hitherto recommended viz, that trial holes should be sunk at Otaki and in the Wairarapa, in hopes of finding a similar old gold drift below the sedimentary tertiaries.
It may still be deemed advisable to try this plan although the chances of success are small. What I fear, from my experience in the Hutt, is that it may be found impossible to bottom in these places without a steam engine, on account of the quantity of water. No further amount of exploration is likely to give decisive information as to whether an older drift lies below, sinking will be the only proof. At one point only, viz., in Palliser bay, is there any evidence and there it is in the negative. The blue clay with its limestone base is there found resting unconformably on the mudstones and slates of the old rocks and there is no intervening old drift.
Believing, as I have before stated, that the gold line or zone lies far to the Westward, I hesitate to commence a work of deep sinking which might involve considerable outlay unless the Government express a wish that it should be tried, even in that case it might be best to do the work by contract.
I have, as far as practicable, followed Mr. Brough Smyth's suggestions as to a search towards the sources of the streams. Putting the native question entirely on one side and the point whether we should be allowed to examine the sources of the rivers in the direction of the volcanic range, and the centre of the island more minutely than I have already done; the fact is that these rivers run through such thicknesses of tertiary rocks (either volcanic or sedimentary) from their sources to their mouths, that prospecting in that direction would mean deep sinking, with powerful steam engines and immense outlay. I therefore say wait for the knowledge which will be gained by the progress of gold finding on a line from Coromandel southward through the Waikato country.
The sources of the Rangitikei are no doubt in the old rocks of Ruahine, but the rocks of Ruahine appear to be similar in character to those of Tararua and the western flank of Ruahine is remarkably inaccessible, from the great thickness of tertiaries lying against it, cut up by deep chasms and covered by dense bush, which is always an obstacle to geological investigations. The accessible side of Ruahine is from Napier. I believe it has been examined from thence and I fear without finding gold, or we should have heard something of it before now. An examination of the Ruahine range from the western side would be expensive and I fear quite unsatisfactory.
I have obtained in late explorations a good deal of information as to the sequence of the old rocks of Tararua but from the absence of fossils and the broken character of the strata it will be some time before these rocks can be mapped with certainty. A line of veins, of a black mineral supposed to be an iron ore is found in all the valleys on the eastern side of the range. These veins are thin and have not yet been found to come together in a decided lode. They are largely developed in the gorge of the Ruamahunga.
The road party on the Petoni road have laid open a lode from which various minerals have been reported to me. I have sent specimens of these vein stones to Melbourne to be examined but have not yet received the report. A similar quartz to what is there found is observed in various places, including the Waikanae river.
In the Otaki and other rivers what appear to be vein stones of carbonate, of lime in soft slate, are found in great quantities. Their existence on both sides of the range, presenting the same appearance makes me doubt that they are vein stones and suppose that they are stratified rocks. They may furnish a supply of lime at all events. They are pyritous as are many of the other rocks and veins.
In my late examination of the river gorges, although many of the sandstones were found riddled by thin veins of quartz, no decided quartz lode was discovered. It is however possible that veins of auriferous quartz may be found although appearances are not favorable.
Although anxiously on the watch for further evidence as to the existence of coal seams in the Province I have been able to add little to my previous discovery on the shores of Porirua harbour.
Either the plant beds found there have been originally deficient in beds of coal, or they represent the remains of a coal field denuded and nearly destroyed, or the coal beds may be buried and hidden beneath the tertiaries of the West Coast.
Fresh evidence ought however always to be carefully looked for. On the shores of the Porirua harbour the strike of these rocks appears to be North and South, but at the gorge of the Otaki river, the strike of what I take to be the mezozoic sandstone would seem to be East and West. Supposing the latter to be the true strike then it is possible that coal seams may be found along the face of the front ranges, at other points than the river gorges, but as at present these ranges and the flat country at their base are so covered as to render geological enquiry almost impracticable except in the river gorges, my advice almost amounts to this. Settle the country and make roads and then perhaps we may light upon the coal.
Igneous rocks, as described in the report of my last journey, are gradually coming to light. As the igneous rocks are deep seated, seldom shewing themselves, may not minerals be deep seated also?
I trace a line of fracture, or of fault, along both sides of the ranges, generally near where the old rocks and the tertiaries meet (although to the northward, in the Opakiplain &c., perhaps cutting through the tertiaries only) showing a thrust of the range upwards. This may have taken place during the earthquake of 1855, or it may have been caused by a succession of upheavals. Near Featherston and at the Waiohine, the height of the thrust may be four or five feet, on the Opaki plain, at some distance from the range, it may be thirty feet and I suspect this line will be found to strike the Eastern scarp of the Puketoe range, with a much greater difference of level at that point.
On the western side of the range at the Manawatu, the lift has tilted the tertiaries rather than broken them, inclining them upwards at an angle of about 20°. Thus, during the earthquake of 1855 the main ranges may have been lifted throughout their whole length, without affecting the level of the tertiaries on the coast,
I believe that I have now rapidly passed in review all the main groups of rocks in the Province although the detail remains to a certain extent to be filled up.
In a topographical point of view the result of my explorations is to show that no extent of farm land is likely to be found within the limits of the mountains of the main range, although in all the valleys which I explored there is more or less terrace land which may be occupied by small farmers but these flats are generally at a considerable elevation (in the gorge of the Ruamahunga, for instance, over 1000 feet above the level of the sea) and in all cases the expense of road making would be great. Considering the deterioration of climate which would probably be caused by the destruction of the forest on the steep ranges and that timber is perhaps the most valuable crop that they could grow, I see no reason to encourage settlement within their limits, except in places not remote from the town and in those valleys which are likely to form lines of communication, such as the Akatarewa, the Waikanae and the Otaki. In the central parts of the ranges nature has had quite enough to do to pack an immense mass of material within a limited area, without leaving any level land.
I attach no importance to the bare ridges of Tararua. The edge of the forest appears to reach a height of 3000 feet or more and the open country above is not likely to be profitably occupied by domestic animals, although it might be well adapted, in these days of acclimatization societies, for turning out Himalayan antelopes, chamois, &c.
The same remarks will apply to the open land of Ruahine which you may have observed from the Patea country.
Colonization must follow the great valleys and plains of the Forty Mile Bush, and the West Coast, and a view from the pass where I crossed the main range,
looking on one side over the Forty Mile Bush and on the other over the Manawatu plain, shows an extent of fertile land, perhaps unsurpassed in New Zealand. The end of Tararua, which here thins out like the point of a wedge, not more than four or five miles broad and 915 feet above the level land, forming the only separation between the fertile plains on both sides.
In fact the gorge of the Manawatu is—the key of the Province—and a few minutes view from the hill above, shews more of the capabilities of the country than days journeys elsewhere.
I have the honor to be,
Sir,Your most obedient servant,James C. Crawford,
Provincial Geologist.
New ZealandGovernment Gazette,
(Province of Wellington.)Published by Authority.All Public Notifications which appear in this Gazette, with any Official Signatures thereunto annexed, are to be considered as Official Communications made to those Persons to whom they relate, and are to be obeyed accordingly.J. Woodward,Acting Provincial Secretary.Vol. X.] Monday, March 2, 1863. No. 12Geological Reports,by theHon. J. C. Crawford, Government Geologist.
I. On the Wairarapa and East Coast.
II. On Mr. R. Brough Smyth's “Notes on the Specimens of Rocks collected in the Province of Wellington.
I.Report on the Wairarapa and East Coast.
Wellington, February 11, 1863.
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Sir,—
After returning from the exploration of the Valleys of the Akatarewa and the Waikanae rivers, I started from Wellington on the 15th of January, with the view of gaining an insight into the geology of the N.E. part of the Province, more particularly in the direction of the Puketoe range, and the country generally, lying between the Tararua range and the East Coast.
Leaving the drift gravel of the Wairarapa behind me at Masterton, I found on rising the bills towards the Taueru station, that I had entered upon the upper tertiary sandstone. This rock I found extending over the whole of the interior of the North-Eastern district, resting upon the blue clay except where some drift gravel intervened between the two, but the gravel is by no means largely developed in this district. Towards the East Coast I found a change of rock, but of this more hereafter.
This upper sandstone consists of a series of soft fine grained sandstones, fossiliferous and alternated with fossil beds almost approaching limestone, and is sometimes of great thickness in this district, seldom less than 500 feet, and in some places I think it must measure 1000 feet.
Some of its fossils are turritella, venus, dentalium, pecten, struthiolaria, I have no doubt that it is of the same age and character as the upper sandstone of the Whanganui river.
This formation, where found undisturbed, seems to lie very horizontal; but numerous hill sides have slipped into the valleys, there giving the strata the appearance, to the casual observer, of dipping in various directions and at high angles.
From the vertical nature of the section in which this series is found exposed, it has been impossible for me to make any but a partial investigation of its different beds, and the same difficulty, you may have perceived in the cliffs of the Whanganui and other Western rivers.
The blue clay throughout this district does not show much of its thickness above the river levels.
Crossing the Manuka range, 906 feet above the sea level, the road drops down to the Valley of the Taueru, and thence on to the Taueru station.
Here I visited a very beautiful waterfall, formed by the waters of the Mangarei, a tributary of the Taueru. The stream falls over a ledge of the upper sandstone to a depth of about fifty feet, into a large circular pool. Hard fossiliferous beds of the upper sandstone form the rocks at the fall, the softer overlying beds, which are found in an adjacent cliff, having been denuded.
I may here state that there is a remarkable parallelism between the effects produced in this district and in that of the country inland on the Whanganui and Rangitikei rivers, inclusive. In both districts are the upper sandstones largely developed, and in both have these nearly horizontal strata been broken up by denudation, into very rugged surfaces.
Many of the beds of the upper sandstone are extremely soft, and therefore liable to be rapidly worn away; some of them, indeed, on being struck by a hammer, instead of breaking into fragments, crumble and run down into pure sand; and water poured upon them passes through as in a sieve.
At the Taueru pieces of marine fossils were shewn to me as quartz; and I found that generally throughout the district calo spar, white limestone, or, as I have said, even fragments of fossil shells, were supposed to be quartz.
Some very perfect “pecten,” from the top of the Maunga Pakeha range, were presented to me by Mr. Varnham, for the museum in Wellington.
On the 19th January, I left the Taueru station and proceeded up the valley of that river, the Forty Mile Bush lying about three or four miles on my left and here covering a very broken country.
The road leads past Mr. Nicholl's, crosses the Taueru, and ascends the ridge on the Eastern side of that river. My estimate of the height of the Taueru station above the sea is 427 feet. The ridge just mentioned rises to 1100 feet, and the Manawa hill next to it, above a run which rejoices in the euphonious name of Boggley Wallah, to 1179 feet. Here one looks down upon Messrs. Jeffs and Riach's head station, and on the valley of the Whareama, with its level flats and swamps, while to the Northward may be seen the country drained by the Matai kuna, the Oahanga, perhaps also the Akiteo and here I could see plainly enough that all within view was of tertiary age, except the blue ridges of Tararoa in the far distance.
At the Manawa hill, I was lucky in meeting Messrs. Spinks and Langdon, proceeding in the direction in which I wanted to go, viz, to Mr. Spinks' out station, Mount Pleasant, or Waitawiti. Our road passed over the highest ridge which I traversed in the district, viz Ngatakitura, which, by a mean of two observations, I make 1210 feet above the sea. From this ridge we descended to Mount Pleasant which is probably the highest inhabited European house in this island, being also by a mean of two observations, 985 feet above the sea level. Notwithstanding the height, it is a very cheerful looking place and it commands an extensive view.
Leaving Mount Pleasant on the 20th January in the direction of Knight's station, we soon crossed the sources of the Taueru, passing therefore again to the Westward of that river, crossed a ridge and came upon the flats of the Waitawiti a tributary of the Tiraumea. As the latter river is a large branch of the Manawatu, we were now therefore, on Western waters.
We crossed another ridge and descended to the Tiraumea, at Knight's station, where the Waitawiti joins that stream. Our descent had been considerable, and Knight's house, by a mean of two observations, is only 414 feet above the level of the sea. Thus it appears that the gorge of the Manawatu must be considerably lower than that height.
The Tiraumea rises to the Eastward of the Puketoe range, runs to the Southward at first and turns to the Westward and Northward round the South end of that range, to join the Manawatu.
The country here is better and less abrupt than that lying further to the Eastward, but it is close to the forest of the forty mile bush.
When the forty mile bush road is made I should suppose it would be easy to open a branch line, by or near the Tiraumea to Knight's station, which would then form the easiest line to the Wairarapa for a good deal of the open country.
An open track of a few thousand acres, called Moroa, lies surrounded by forest, between the Tiraumea and the Taueru, about six miles below this.
The Tiraumea has at present very little water in it, but I am informed that in a fresh, canoes can ascend about three miles beyond Knight's.
In its bed I found a boulder with plant impressions.
I would now call your attention to the Puketoe range, which has been in sight for the last two days, and where we may be said to have arrived, for Knight's station is on its lower spurs. I believe a great deal has been expected from this range in a mineral point of view, perhaps because it is remote, and difficult of approach. My first view of its outline settled its character in my mind and a close approach confirms the first view.
It is clearly tertiary, of the same age and character as the country I had traversed, but attaining a somewhat greater elevation. The additional height and its scarped cliffs, lead me to suppose that it marks a line of fault, or slip. I need hardly add that metals cannot here be expected.
The ascent of the Puketoe from Knight's would be troublesome, although the distance is short. A succession of sharp wooded ridges intervene. It looks to be easier of access from the North East.
I do not suppose the height of this range to reach 2000 feet. Supposing it to be 500 feet higher than Ngatakitura, this would give an elevation of 1770 feet above the sea. There may be some open land on the top of the range, but the greater part is covered with bush.
At Knight's I found the blue clay, and on the ridges above, upper sandstone beds, with turritella, venus, struthiolaria &c., From Knight's it is impossible, at present, to get a horse through the bush to the gorge of the Manawatu, which, as the distance is short, might be easily rectified. The view this day extended over the sources of a number of rivers, the Tiraumea, the Taueru, the Whareama the Mataikuna, the Oahanga, and perhaps the Akitio: open country to the Northward and Eastward, bush to the West, beyond which the Tararua is seen in the distance. On the Tiraumea there appears to be a good deal of totars.
From Knight's I returned to Mount Pleasant.
It had often puzzled me why the alluvium of the Wairarapa should be of such a different character to that of the Hutt, but I think I have now solved that problem. The Taueru from its source to its exit in the Ruamahunga, passes entirely through soft tertiary rocks, and I believe it to be from their degradation, that the peculiar character of the alluvium of the lower Rumahunga is derived.
On January 21st I left Mr. Spinks' hospitable mansion, and proceeded to the Eastward, again crossing Ngatakitura and Manawa ranges. From the latter the road drops down to the valley of the Whareama, near the junction of the Makirikiri with that stream.
Here I again found the usual upper sandstone fossils. About two miles further down I reached Ngapapatu, Messrs. Spinks and Langdon's head station, which I make only 143 feet above the sea level. I now began to perceive signs of a geological change. Still proceeding downwards I crossed the Whareama, passed over a hill and descended upon the Tinui station, situated upon the flats of that stream, a tributary of the Whareama.
Immediately above the station is one of those remarkable hills called Taipos, which I accordingly proceeded to examine. These hills have an extremely fantastic, picturesque and rugged outline, and at first give the impression of volcanic peaks, but on examination prove to be our old friend the upper tertiary sandstone, tilted at an angle of about 70°, and dipping to the Westward; the harder parts of the strata sticking out in peaks, while the softer parts have been worn away.
On the top of the Tinui taipo I obtained turritella, venus, dentalium &c., Its height is 975 feet: Here also I found the Matai kuna taipo bore N 50° E, Buxtons taipos S. 20° to 30° W, and what I supposed to be Moore's taipos S. 15° W. W. It will thus be seen that the several peaks are nearly, but not quite, in a straight line.
Proceeding on the 22nd towards the coast, the road passes for a short distance up the valley of the Tinui, where I think I found the blue clay. Crossing that stream I ascended a ridge 828 feet high, where a fresh geological series is found, consisting of white limestone and calcareous grits, and in their midst, a fine grained greenstone, looking like a Syenite, which is doubtless the intrusive rock that has tilted the strata. It appears to have brought up the calcareous rocks, dislocating and tilting the upper sandstone at the same time.
If you refer to my report of October 24th, 1861, you will perceive that I describe calcareous rocks, highly inclined on Messrs. Barton's and Riddiford's stations. White Rock and Teawaite. I had now clearly found the continuation of the same series, and more than that I had found “in situ,” the dislocating and upheaving rock. The Hornblendie pebbles found in the bed of the Upoko Ngaruru must also have been derived from another variety of the intrusive rock of the same age, and from my previous traverse in that direction, to Messrs. Beetham's station, I have quite sufficient evidence to establish a line of dislocation and upheaval, extending about N.N.E. from the White Rock and Teawaite stations, the action along which line has exposed a series of calcareous rocks, thrown up the strata of the upper sandstone at an angle of 70°, and probably bent and folded a series of tertiary rocks which I was now approaching on the East Coast.
Descending from the calcareous ridge to the valley of the Whakatake the road follows that stream to the sea, and thence South to Castle Point. We now find a series of thin and soft beds of sandstones and mudstones, cropping out on the beach and in the vallies, sometimes nearly horizontal, and sometimes inclined at high angles. What relation these rocks have to the limestones and calcareous grits, I am at a loss to determine, for I could not here find a section which would throw light upon the subject. My impression is that they overlie the calcareous rocks and at the period of dislocation were rucked up on the back of the latter by the force of the upheaving power.
In these sandstones and mudstones I found small seams of coal and numerous impressions of vegetation, but none clear enough to be enabled to judge of their age, but as the coal-seams appear to be lignite, or brown coal, I have little doubt that we may put them down as of tertiary age. In fact I believe them to be of the same age and character, as the coal shales of the Whanganui River, mentioned in my letter of February 17th, 1862.
The history and age of the calcareous rocks will I believe be best obtained on the Teawaite station, where they approach the sea. They must not be confounded with the upper tertiary fossiliferous limestone of Tepurapura and elsewhere, which seems to be found in patches only.
On January 23rd I examined the reef at Castle Point. This reef is a peninsula forming the shelter to the anchorage. Both it and the rock called the Castle are composed of calcareous sandstone, resting unconformably on the sandstones and mudstones just mentioned. In it I found venus, pecten, terebratula, ostrea, turritella, struthiolaria, &c. The reef, which is a ridge perhaps fifty feet high, is penetrated by a cave, through which the tide passes and in which the roar of the wind and waves is very striking. Between the reef and the Castle Rock, the sea has another passage through the rocks into a basin. The Castle Rock is of similar formation to the reef.
In the mudstones and sandstones on the shore I found plant impressions, and in consequence proceeded in the afternoon up the bed of the stream behind Castle Point in the hopes of falling in with some seams of coal. I went on as far as I could penetrate, perhaps three miles, finding plenty of plant impressions, but no actual coal seams.
Mr. Guthrie informs me that some years ago, one of his shepherds, who has since returned to Australia, brought in a handkerchief full of coal, (stating that there was plenty more where he found it) which burnt well and seemed of good quality, and which must have been found within three miles of the Castle; but unfortunately he had neglected to ask him where he got it.
The coal question in the East Coast District may be put as follows.
My impression is that the mudstones and sandstones of the coast are of tertiary age and therefore if any workable coal seams are found in them, that the mineral will be of inferior quality, but there are the little known calcareous rocks to be considered.
Now, at the Kowhai coal fields in Canterbury, there are calcareous rocks in the vicinity similar to the white limestone of our East Coast, and although Mr. Haast, at the time of my visit to that coal mine, had been unable to determine any connection between these rocks and the coal, yet he had a strong suspicion that they formed part of the series. Consequently, although I have seen no indication of coal among the calcareous rocks of the East Coast, except perhaps at Teawaite, I think we have at all events some reason to expect the possibility of its being found; and as from the broken nature of the country it might take years for one individual to explore it thoroughly, I would suggest that a reward for the discovery of the outcrop of workable seams of coal, might stimulate the perceptive faculties of shepherds and others, whose daily avocations lead them through the defiles of these regions.
On the beach here is some iron sand, whence derived it is difficult to say, unless it comes from the intrusive greenstone.
On the 24th January, Mr. Thomas Guthrie kindly accompanied me to point out some coal seams on the shore. Near the Nakaua river we found soft sandstones containing plant impressions and some coal seams about two inches thick. They were not continuous, but thinned out in a yard or two. The rocks are the same as those at Castle Point and dip slightly to the Westward.
Ascending from the beach in about a mile, I again came upon the calcareous grits and the intrusive greenstone, both of which prevail in crossing the Trooper, the ridge separating the Whareama from the sea. 896 feet I make the height of this ridge.
From this range the Puketoe is visible, its tertiary character evident from this distance.
Descending from the Trooper, I crossed the alluvium of the Wharehama Valley, and ascended the hill next to Buxton's Taipo, composed of calcareous grit. The Taipo has a singular family resemblance to that at Tinui and also dips to the Westward. I thence descended to Telford's station, Awa toe toe, 136 feet above the sea.
Leaving Mr. Telford's on January 25th, I continued on the calcareous grits for about a mile, when the upper tertiary sandstone rocks again appeared. and I found turritella, venus, &c. The upper sandstone now continues all the way to Collins bush, resting on the blue clay, or possibly in places on gravel.
The road crosses a ridge and descends upon Biscuit Creek, crosses another ridge and descends upon the Kaumengi, crosses a third ridge and descends upon the Taueru, crosses a fourth ridge and descends upon Te Ore Ore: the average height of the river flats being about 400 feet and of the ridges, where the road crosses, about 900 feet above the sea.
Reaching the Ruamahunga the upper sandstone has been left behind, and the drift gravel appears.
Stopping at Masterton for the night, I was informed that the plant beds of the East coast extends for a considerable distance up the Oahanga river.
In this journey I have settled the character of a large block of country, viz.,—the whole of the island within this Province lying to the N. E. of the Wairarapa, and between the Tararua and the East coast. It will of course be desirable to complete a traverse which I propose to make with you, from the gorge of the Manawatu to the Akitio river and the East coast, but as I have been through the gorge of the Manawatu, and as I have also been on the Rua Taniwha plains and at Porongahau, I may very safely venture to predict that in the above named traverse, we shall find nothing but the above described tertiary and other rocks.
In none of these tertiary rocks can metallic ores be expected, (although the intrusive igneous rock may contain a little gold), nor do I expect any in the limestones and calcareous grits, for the following reasons.
1st. Because I see no indications of mineral lodes among them.
2nd. Because, although I have been unable to detect fossils among them and therefore cannot as yet assign to them their geological age; if not older tertia ries, from their lithological character they can hardly be older than of Mezozoioc age, and therefore, supposing them to be of that age, although coal may be looked for, one cannot expect to find any of the metallic ores among them, save possibly ores of iron, of which however there is no appearance.
The date of dislocation and upheaval of these rocks would also, I imagine, militate against the argument of their containing metalic ores (there being no appearance of any previous disruption of these rocks which might have charged them with minerals). The intrusive plutonic rock must have penetrated them after the deposition of the upper sandstone, therefore probably in the Pliocene. or Post Pliocene era.
You will perceive that we have now established three nearly parallel lines of plutonic or volcanic action in this Province.
In the centre, the ancient rocks of the Rimutaka, Tararua, and Ruahine, with their spurs, folded and pressed together, and having a general direction of about N.N.E. true.
In the East, the calcareous and tertiary rocks, tilted on a line of about N.N.E. (magnetic) from the ancient rocks of Cape Palliser towards the Province of Hawke's Bay. In the West we have part of the volcanic chain of Ruapehu and Tongariro, ending abruptly, however, at the southern slope of Ruapehu, and perhaps I might include a fourth line in that neighbourhood, in the Kaimanawa range, but it is hardly in the Province.
From the central chain on both sides tertiary rocks extend East and West. I have therefore narrowed the area in whcih
metallic ores may be sought to the main central range above described, the Kaimanawa range in the Taupo country and the Aorangi range at Cape Palliser, save and except the chances of finding gold below, or in, the drift of the Wairarapa and the West Coast.
On the 26th of January, I returned to Wellington, with the expectation of finding a report from Melbourne, upon specimens of rocks which I had sent there for examination; in this I was disappointed, and as I had a little time to spare before the arrival of another mail, and found that some curiosity existed as to the results of a recent journey to the top of Tararua, by the valley of Wai Ngawa, I proceeded to Greytown on February 3rd, with the intention of making the ascent of that mountain.
However, after several days attempt to get hands to accompany me, I found that owing to the harvest and the bush fires I could neither get white men nor maories to undertake the journey at this time.
Mr. Thos. Kempton, who offered to go as guide, gave me however a very clear andintelligent account of his late journey. He appears to have travelled up the bed of the Wai Ngawa for three days, before emerging from the bush, and at a great incline, he thinks often three feet rise for four in advance. He then came out upon a grass country, extending to the top of the mountain, the vegetation consisting of a new sort of tussae, the common spear grass and the broad leaved spear grass (no doubt the “Spaniard” of the Middle Island) and wild parsley, which I suppose to be anise. To any one who knows the Middle Island the vegetation speaks for itself. He had reached the zone of glass, above the usual forest zone.
Arrived at the top he saw range after range to the Westward, of the same character, with bald grassy tops above the forest zone, and apparently nearly, if not quite, of the same height as the range on which he stood which shut out the view of the West Coast.
It is evident enough that the grass country must be covered with snow all winter. If it can be made of use, Mr. Kempton recommends a line to be cut into it by a leading spur opposite Ray's. On the descent he found out a better line ef road which would shorten the ascent by a day. He describes the rocks as similar to those of the Rimutaka hill.
As all the rivers on that side of the Rimutaka and Tararua bring down similar gravel, this was to be expecied, as the parallelism of the formations is obvious.
During this journey I felt two shocks of earthquake. One on Febuary 4th in the Upper Hutt, about 7. 15. a. m. the other on the 7th at Greytown, about 2 50. p m. Both were rather smart shocks.
On my return to Wellington on the 9th I found the expected report from Melbourne had arrived, a consideration of which I will reserve for a separate eommunication.
I have honor to beSir,Your most obedient servant,James C. Crawford
Government Geologist.
II.Report on Mr. R. Brough Smyth's “Notes on the Specimens of Rocks Collected in the Province of Wellington.”
To His HonorI. E. Featherston,
Superintendent of the Province ofWellington.Wellington, February 14th, 1863.
Sir,—In forwarding to you a copy of a report which I have received from Mr. Brough Smyth, of Melbourne, on specimens of rocks sent by me for examination, from various parts of this Province, I shall take the opportunity to point out what my plan of operations has been, and also show wherein I agree with Mr. B. Smyth's very able and valuable suggestions, and where, from causes of which be would necessarily be unacquainted, his views cannot perhaps be carried out.
In proceeding with the Geological Survey of the Province I have thought it advisable, first of all, to obtain a general knowledge of the whole rock formations within its limits; so that when it became necessary to employ men upon the Survey, I might be able to go on with continuous work; otherwise they might have been frequently unemployed, waiting for me to know in what direction to turn.
The kind offer of the Honorable G. S. Evans, Postmaster General in Victoria, to submit specimens of our rocks to the “Savans” in Melbourne for examination, came in aid of my views, and is the more useful, as we have no analytical chemist in this Province, and that, should I attempt to assay minerals myself, it would take up much time, probably the results could not be relied upon, and even the necessary re-agents and laboratory
plant cannot be procnred without sending to Australia for them.
I therefore collected and sent to Melbourne specimens of rocks from many parts of the Province, but more particularly from these ranges, and awaiting the report, I made such excursions, especially those doscribed in my last letter to you of the 11th instant, as, combined with my explorations last year, enable me to grasp all, or nearly all, the leading Geological features of the Province. By this means I have narrowed the area within which the search for minerals may be expected to be successful, to the main ranges of Rimtaka, Tararua, and Ruahine, with their spurs; the Aorangi range at Cape Palliser, and the Kai Manawa range in the Taupo country. I except coal, of which more hereafter.
You will observe in Mr. Brough Smyth's report, that granite appears among the specimens sent by me from the Upper Hutt. This confirms the opinion of that eminent geologist, the Rev. W. B. Clarke. Doubts, however, having been expressed, I have preferred waiting for confirmatory evidence before announcing the fact.
The theoretical proof which I gave in my letter of December 18th. 1861, of the existence of the “gold constants” in these ranges, is now confirmed by the discovery of granite, combined with the evidence of the ancient character of the bulk of the stratified rocks.
The granite is found in the ridge behind Mr. J. Brown's, in the Upper Hutt, which bounds on that side the Mungaroa swamp; and I have also found it on the Mungaroa Hill. It is very fine grained, and may easily be mistaken for a sandstone. It will doubtless be found nearer Wellington, and may come into use as a building stone. Near it is sandstone with quartz veins, and mudstones of two kinds, but I cannot yet say in what sequence.
With regard to metamorphic rocks, although the semi-orvstalline sandstones and other rocks may be said to be of that character, yet as there are neither gneiss nor mica schists within these ranges, it will be advisable to abandon the term as applied to the rocks generally. The fact is, that the more the country is examined, the less metamorphic do the rocks appear.
Thin quartz veins appear to penetrate many of the rocks of these ranges, riddling them in all directions; but the larger quartz lodes are by no means so prominent as in the gold regions of Australia. That powerful lodes of quartz and other vein stones however traverse the rocks, every exploration tends to show; and I can mention one quartz lode fifteen feet wide and many others besides of considerable thickness. I believe the geological hammer now requires the aid of the pickaxe and crowbar, to expose the mineral veins.
Quartz lodes and other mineral veins seem principally exposed in the fractures of the anticlinal axes, which bears out my original impression that minerals will be found to lie deep, and this view will also affect the argument as to the locality of alluvial gold diggings.
If gold lies deep in the rocks while “in situ” the wearing away of these rocks (particularly as here in deep and steep vallies) will deposit it in the lower vallies only, and it may be plentiful there, while entirely absent from the higher ground.
It is suggestive that the rock taken from Mr. Barraud's well should resemble rocks from a district where sulphide of antimony and ohrome iron are found, these being two of the minerals reported in the pyritous quartz lodes of the Petoui road. The sandstone with plant impressions, (No. 37,) from Porirua, being decided, on the high authority of Professor McCoy, as of mezozoic age, which with regard to coal, means oolitie, (the age of at all events the upper beds of the Australian Newcastle coal seams); and the mudstones being declared Palæozoic and probably silurian, it follows that we have sedimentary rocks of two eras in these ranges, folded however together in such a way that I foresee great difficulty in drawing the line of demarcation.
Mr. Brough Smyth's remarks with regard to gold seeking show a masterly grasp of the subject.
A reference to my letter to you of October 21st 1862, will show that I have most faith in gold being found, in the North Island, in the continuation of a line from the Middle Island Gold Fields to Coromandel, and that the present evidence is in favor of micaceous and talcose schists as the best gold bearing rocks of New Zealand; but I have also strong reasons to show, why the search for drift gold in this Province should not be hastily abandoned. I will first of all dispose of Barraud's well. This well is sunk for a few feet only through a sandstone and a felspatho siliceous rock. These rocks were said to be intersected by a vein stone, which was covered with rubbish when I visited the well, and unfortunately on the following day it was bricked up. There is neither drift nor
alluvium above the rock and only an inch or two of soil.
That gold dust might have been thrown into the well is possible; but the specimens sent to Melbourne were collected from the rubbish heap afterwards, and therefore not likely to contain any foreign mineral. I shall endeavour to make a further examination, particularly as more grains of gold are said to have been found in the neighbourhood and as I see some appearance of mineral veins close at hand.
I must now make some small corrections as to Mr. Brough Smyth's idea of our mountain chains. His view is, naturally enough, that our main ranges throw off spurs East and West, spreading across the country, whereas the remarkable feature is this, that the mountain ranges of the Rimutaka, Tararua, and Ruabine, including all the mountainous country in this neighbourhood, pass like a wall to the N.N.E. the spurs keeping on the whole the same direction as the main ranges. Of course one does not speak of a wall as built by a stone mason, a rigid line, nor do all the spurs and ridges adhere to a strictly N.N.E. course, but such is the main direction. The main strike of the rocks, being I should say about North (magnetic), with however many exceptions.
Most of the maps give an erroneous impression, by marking a range, curving from the Ruahine N.N.W. towards Taupo, which range does not exist, although the broken tertiary plateau may there reach an elevation of 2,000 feet.
For a description of the volcanic chain or block of mountains of Ruapehu and Tongariro, see my report of February 17th, 1862.
In its broadest part, from the coast opposite Mana to the Wairarapa, the main range does not appear to exceed twenty three miles wide. At the gorge of the Manawatu, the breadth following the curves of the river, is only about seven miles.
These mountains have assumed their form, less from upheaval than from lateral pressure. The strata are accordingly bent and folded upon each other, and the ranges are separated into a succession of sharp and nearly parallel ridges, culminating in height towards one or more central axes, but high and abrupt also at both sides, where the sea, or the tertiary rocks, meet them in a horizontal, or nearly horizontal line.
One consequence of this conformation is that the rivers, while within the ranges, run in ravines, rarely as in the instance of the Hutt, expanding into vallies.
If we take the valley of the Hutt as an anticlinal axis near the centre of direction of the range, we there find, in the central axis, the granite of the Upper Hutt and Mungaroa; but I have strong douhts whether we shall find it on the surface in the high parts of Tararua, although it may be assumed to form the hidden nucleus of that range. The basalts, like the dtorite rocks of the Canterbury Province have not yet been found “in situ,” and are not likely to appear in a prominent way; and the only rock which I can venture to call lava, in this main range, is the red rock of the Rimutaka, (on the authority of the Rev. W. B. Clarke,) but where it is found, and elsewhere in these ranges, there are no signs of volcanic vents.
The stratified rocks, sand stones, mudstones, slates &c., seem to, and I think will be found to continue to, occupy the main part of the ranges.
The accumulations of drift on the Eastern side of the ranges are fully equal to those on the West, and the tertiary rocks may be said, with some exceptions, to be of the same character and thickness on both sides of the main range. Mr. Brough Smyth, suggests as particularly worthy of immediate attention, the basins of the Hutt, the Waikanae, the Otaki, the Manawatu, the Rangitikei, and the Whanganui. I would omit the word immediate in reference to the three last named of these rivers and substitute for their names those of the Ruamahunga, and its tributaries on the right bank, the Waipoa, the Wai Ngawa, the Waiohine and the Tauhere Nikau, (perhaps this last cannot be called a tributary.)
Although I should like to see the head waters of the Whanganui prospected, yet, even supposing the natives would consent, the expense of a party would be enormous in proportion to the work done. I only found about two yards of the ancient rocks during a journey of some hundreds of miles in that direction, and then in the bed of the Waipare, a tributary of the Whanganui, with the hills, formed I believe of tertiary rocks, rising at an augle of 450 or thereabouts, on both sides, to a height of say 700 feet above the bed of the stream. I consider that the Upper Whanganui, must wait the progress of development of the gold fields from Coromandel through the Waikato country, which may throw sufficient light upon the subject.
The same remarks will apply to the Rangitikei River, and those rivers lying between it and the Whanganui. The heads of these rivers would answer Mr. Brough Smyth's idea of searching towards the sources of the streams, but a prospecting party to explore them must be fitted out
and kept supplied at great expense and must be prepared for very deep sinking, and as yet there is no road.
With regard to the Manawatn, although old drifts may lie beneath the tertiaries on its banks, and may eventually be worth sinking for, if we find any reasons to warrant the outlay. the river itself is most unlikely for gold. It presents the curious feature of rising in the lertiaries of the East Coast, bursting through the main range and thence again passing through tertiaries to the sea. The whole course of the river through the ancient rocks does not exceed seven miles and its stream there occupies the whole breadth of the channel.
Immediate exploratious of the Hutt, the Waikanae, and the Otaki, with the Eastern Rivers previously named, I particularly concur in, for reasons which I shall presently show.
This brings me to the main point of my argument, which is, if gold exists where is it to be found, as drift and alluvial gold?
I have endeavoured to show the character of the mountain range and from this it will be seen that in general the rivers while confined to the range, run in very narrow and perpendicular channels. After entering the mountains and ascending for a few miles the beds of the streams, the ascent is rapid in the extreme, the drift disappears and the waters rush over a rocky bottom, or over large boulders of the surrounding rocks, and therefore drift gold, if present, could only be worked for a comparatively short distance up the mountain beds of those rivers.
Old drift gravels and clays may certainly be found in various places on the hills, as on the Mungaroa hill to a height of between 700 and 800 feet, but in general the rock is covered by a thin stratum of soil only, and where that is he case of course there are no diggings.
If we then consider the great denudation which has removed the rock from these vallies, say in the glacial epoch, we may ask where has the material gone to? The answer is obvious. It does not lie, or only to a small extent, within the hills, but has been swept into the Wairarapa country on the East, into the basiu between Kapiti and the main range, on the West; and into the Hutt Valley on the S.S.W.
If these rocks contained gold, most, if not all it of would follow the same route.
I therefore would suggest that in a search for drift gold attention should be first directed to a careful examination of the Valley of the Hutt; and also, what I have already hinted at, that the question of grappling with deep sinking in the Wairurapa and perhaps also on the West Coast should be considered, combined with an investigation of the river beds previously mentioned as far as practicable.
As Mr. Brough Smyth also suggests that gold may be looked for in unexpected formations. I would not omit the blue clay. Although it is a fossiliferous rock it has a great appearance of being a drift formation, and I submit the following theory of its deposit, say to the Eastward of the Rimutaka and Tararua.
Suppose great degradation going on in the glacial epoch, along the Eastern vallies of these ranges and the materials carried to the Wairarapa,—what would be the natural order of deposition? Why that the heavier boulders would be left in the vieinity of the range, while the lighter particles of earth, clay and sand would be carried to a greater distance. As a consequence one may expect both deposits to be, in places near the line of demarcation, mixed together; and as the lighter materials would be soonest exhausted, a deposit of gravel would latterly form over the clay. All this is carried out as far as I can yet speak. I have not as yet been able to find the blue clay to the Westward of the Ruamahunga, and the other conditions are found towards, and to the Eastward of that river. The elevated beds of gravel and blue clay, lying still farther to the Eastward, might not at that time have been upheaved by the force along the axis of elevation of the East Coast. Now, if the denuded rocks were gold bearing, most of the gold would be deposited, with the heavy gravel, near the mountains, but lighter particles might accompany the blue clay to a greater distance.
On the other hand the gravel and the blue clay may mark different, although consecutive periods.
The gold question will not be set at rest until the Wairarapa and the West coast plains are bottomed at several points.
Now that I have acquired a general knowledge of the rocks of the Province, I quite agree with Mr. Brough Smyth, that my attention should be directed to a minute investigation of some limited district. What I should now propose, with regard to the Geological Survey and apart from a search for gold, would be to make a detailed survey of the rocks of this range from East to West, mapping them and collecting specimens of every stratum,
taking for the purpose the only lines on which anything like a complete detailed survey can be made, viz, the scarped ends of the ranges from Terawiti to the Wairarapa and the next section further North, from the sea beyond Porirua, up the line of road to this harbour and thence over the Rimutaka to Featherston.
These traverses are absolutely necessary to show the sequence of the rocks and form a basis for further explorations, and as I find fresh mineral veins every time I cross the Rimutaka, we might expect to make some valuable discoveries. But I should like first to know the views of the Government as to the duty of the Government geologist in a search for gold.
Ought I now merely, as above, to point out the proper localities in which to look for that metal, and leave it to private enterprize to complete the research; or would the Government wish me to examine for the above purposes the localities indicated, viz the vallies of the Hutt &c.
In the latter case I should require a properly appointed party of three or four men, with tents, tools, a Californian pump, and a pack horse, with a good foreman, while if the search for gold should be left to private enterprize, a smaller party would suffice for the detailed survey.
Such an undertaking as the bottoming of the Wairarapa valley would necessarily require special consideration and authorization, for although a small sum might suffice for the work, yet unforeseen difficulties in depth and in the influx of water might arise.
In my letter of December 13th, 1862, I mentioned the discovery of the plant bed series of the Porirua harbor. Since that time I have discovered similar organisms in different directions—at Ohariu, on the banks of the Aka-tarewa, and on the Belmont line, and Mr. Mantell has even found them at the top of the Kai-warrawarra road. As Professor McCoy has decided these rocks to be carboniterous, of the oolitic age, I would fain hope that workable seams of coal will be found, and although appearances are not very encouraging, yet, after having seen the manner in which the Kowhai coal seams at Canterbury were hidden by drift, it will be a long time before I shall despair of success.
The traverse and survey of the rocks which I propose to make from the West coast to the Wairarapa by the line of road, would be a necessary preliminary to the search for coal.
I have discovered a black mineral at various points on the Rimutaka, hill, but its character is not yet determined.
For political reasons, it would probably be best that deep sinking should be tried in the Wairarapa, before attempting it on the west coast.
Mr. Brough Smyth will perceive why more attention has been paid to the discovery of quartz veins than of alluvial or drift diggings. The mass of drift having been thrown out of the mountains upon the adjacent plans or basins, rather than deposited within their own area, in a position which often renders it difficult to tell its thickness, or what rocks may lie between it and the undulation of the ancient rocks, I required some support to back my opinion in favour of deep sinking in the plains or basins. You will also observe that the country covered by horizontal tertiary formations can, for all present purposes, be disposed of geologically with great rapidity, while the inclined rocks of the main range require a most patient and searching investigation.
I have proved the “gold constants,” and I have obtained strong evidence in favour of the probability of finding gold. But should the “gold constants” prove inconstant, and the precious metal elude our search, there is no reason to despair of making discoveries of other valuable metals. I have every reason to think that these ranges are full of mineral veins, and at the present moment I await reports on the character of those already found; but at the same time, I suspect that our mineral wealth lies deep, and will require an expenditure of skill, capital, and patience for its developement.
I have the honour to be
Sir.Your most obedient Servant,James Crawford,
Government Geologist.
[Enclosure.]
Mr. R. Brough Smyth's Notes on the specimens of rocks collected in the Province of Wellington by the Honorable J. Coutts Crawford.
Melbourne, January 13th, 1863. I have carefully examined the specimens of rocks brought from Wellington by the Honorable G. S. Evans. I have also read the printed reports of excursions made by Mr. Crawford in that Province, and the MSS. accompanying the specimens.
I have had some difficulty in fixing the several localities (not being provided with a good map) and I have not been
able to gather any information relative to the extent of the areas occupied by the several rock formations. Under these circumstances it is necessary to speak cautiously and to draw conclusions only when the evidence is clear.
Amongst the more important specimens of rock submitted, I recognise mudstones, similar in lithological character to the rocks occurring in the basin of the river Yarra, greyish blue mudstones with iron-pyrites and thin veins of alumite containing more or less silica, and quartz.
I also observe a very fine grained granite rock, and a rock, evidently derived wholly from the degradation of this, consisting of quartz, felspar aud mica, with included pebbles of quartz.
Much of the granite rock contains veins of quartz.
Judging from the specimens submitted, it would appear that part of the valley of the Upper Hutt is occupied by plutonie rocks, but how far these extend, or whether the quartz veins intersecling the primary rocks also run into the granite, it is impossible at present to say.
In Mr. Crawford's report, dated the 24th October, 1861, it is stated that the metamorphic rocks fill a large area and compose the Rimutaka and Tararua ranges, but I do not recoguise amongst the specimens any gneis, clay slates, or mica schists.
I regret that Dr. Evans' hurried visit did not admit of Mr. Crawford's giving more information respecting the quartz veins of the Province. I observe specimens of ferruginous quartz, milky quartz, and much chalcedonic quartz, but how the veins occur, or whether they are thick or thin is not stated, without this information it is impossible to give any useful opinion respecting them; for hand specimens may be obtained abundantly where the veins are thin, and, comparatively, few and unimportant.
One very interesting specimen of basalt, with glassy crystals of felspar, a fragment of a boulder from the bed of the Hutt, would indicate that igneous as well as plutonic rocks may be looked for in that part of the basin.
A fragment of a purple slate rock, marked “Hawtrey, Johusonville” appears to me to be important in connexion with the specimen of quartz No. 11, from the same locality.
All the rocks, including the quartz and excepting the granites and conglomerates contain more or less iron pyrites, and the specimens taken from Barraud's well, which contain alumite, resemble very much the mudstones of the Heathcote District, where we find gold, sulphide of antimony, chrome iron, and a mineral resembling bournonite.
I submitted the fragment of sandstone marked No. 37, to Professor McCoy. He at once pronounced it as of mezozoie age, and similar to the coal formation of Merino in Victoria.
The other specimens are devoid of fossils, but the mudstones may, I think, be safely set down as palæozoic.
With but imperfect means of coming to a conclusion, it may be said that the rock formations of the Province of Wellington comprize
Recent accumulations.
Tertiaries, age unknown.
Carboniferous rocks of the Oolitic age.
Mudstones, probably Silurian.
Granites and other plutonic rocks.
As the discovery of gold in remunerative quantities would no doubt bave a most beneficial influence on the future prospects of the Province, I would recommend that the recent drifts should be carefully examined. Attention seems to have been directed rather to the quartz reefs than to these., but it must not be forgotten that elsewhere gold occurs in drifts and in Post pliocene accumulations in quite sufficient quantities to pay for working, in the midst of primary rocks in which there are but very thin and apparently unimportant veins of quartz, the exploration of which would never reward the enterprize of the quartz miner.
If the suite of specimens forwarded by Mr. Crawford fairly represent the rock formations of the Province it may safely be asserted that the search for gold may be prosecuted with every prospect of success. I have not yet had time to analyse any of the specimens, or indeed to apply any but the slightest chemical tests to one or two, and theretore I cannot say whether or not they contain gold, except as regard the fragments of rock and clay taken from Barraud's well. In these I detected a very small grain of gold.
Whether the gold found in the well is derived from small veins of quartz penetrating the mud stones, or whether there is a thin surface stratum overlying the older rocks which is auriferous, is well worth investigating, and I would recommend that the locality should be catefully examined. What is the prevailing rock in this neighbourhood? and has it been ascertained whether or not
the surface soil is auriferous? Is there any reason to believe that gold dust has accidentally fallen into the well and become mixed with the debris there? These questions would be answered by a not very laborious investigation.
Wherever we meet with silurian (or older) rocks intersected by veins of quartz, we may look with confidence for the discovery of metaliferous and mineral veins of more or less importance. It appears that we have all the conditions in the Province of Wellington. If I were to submit many of the rocks collected by Mr. Crawford to any gold miner in Victoria, he would recognise them at once as precisely similar to those occurring on some of the Victorian gold fields; and while a few specimens of the milky and ferruginious quartz are quite like our own, the chalcedonic quartz exactly resembles that found in the Northern gold fields of New South Wales. Without attaching too much importance to these resemblances (for quartz veins are not always auriferous) they yet serve to show the necessity for earnest and careful exploration of the country.
Looking to the physical geography of the North Island of New Zealand, one observes a main chain of mountains, running generally in a Northerly direction with Easterly and Westerly spurs of considerable extent. The position of this main chain (broken as the other lands may be) has determined the course of the principal river basins, the more important of which lie on the. West side of the main range, If a geological map were constructed of this country it would not probably differ, in its main features, from many parts of Eastern Australia. We should find, I apprehend, the central axis composed of rocks of the primary age, with masses of intrusive granite, and many of the spurs of basalts and lavas of different ages. We should also find areas occupied by carboniferous rocks, and large tracts covered by tertiaries of greater or lesser thickness.
Though the information I have received is not very complete, it would appear that on the Eastern sea board rather thick tertiaries prevail (probably of the same age as the Murray tertiaries.) and I would therefore recommend that the rivers flowing to the Westward should be first explored. There, I am led to believe, the quite recent accumulations of drift, similar to these occurring on our Victorian gold fields, are prevalent, and no very costly examinations would be required to ascertain whether or not these recent accumulations contain gold, or tin ore, or the ores of other metals, in remunerative quantities. There is no reason to believe that gold is more likely to occur on the Western side of the main chain than on the Eastern. But it is probable, owing to the local distribution of the rocks, that it will be found more easily on the Western side. The rivers in Victor'a on the Eastern side are all auriferous.
I would suggest as particularly worthy of immediate attention the basins of the Hutt, the Waikanae, the Otaki, the Manawatu, the Rangitikei, and the Whanganui.
Unless careful attention be directed to the conditions under which gold occurs, a long period may elapse before any important discoveries are made in this part of New Zealand. Looking alone to the modes of occurrence of gold in Victoria, people in other countries may utterly neglect the most important localities, because the conditions there are not the same as here. In Victoria we find the silurian and metamorphic rocks every where intersected by veins of quartz, varying in thickness from a line to fifty feet. These quartz veins, nowhere, it is believed, penetrate the great masses of piutonic rocks which every where have broken through the sedimentary strata. They stop short at the granite boundaries, and the gold miner, accordingly, as a general rule, neglects the granite country. This peculiarity is due probably to the relative ages of the granites and the sedimentary rocks. The force which rent asunder and left wide fissures in the clay slate and schist formation was perhaps exerted before the granites came to, occupy their present place, or perhaps the force was insufficient, or exerted so as not to affect the denser, tougher and harder plutonic rocks. It is a local peculiarity, not a condition universally occurring. Elsewhere gold is found in granite, in gneiss, in mica schist, in syenitic porphyry, in green stone, as well as in quartz veins intersecting rocks of the silurian age.
It may be looked for, and yet may be profitably worked in conglomerates much older than tertiaries.
Gold is found in quite modern drifts overlying granite rocks—not derived from auriferous quartz veins penetrating the granite but from veius in slate rocks which have wholly disappeared. The slate rocks have been denuded and their rich stores of gold have been left in holes and “pockets” of the granite, the bed on which the slate rocks were originally reposing. A granite country therefore (more especially if in the neighbourhood of schists) should not be neglected, but
explored carefully and anxiously. The gold said to have been found in Greaves Gulley, may have been derived from auriferous veins penetrating sedimentary rocks, or it may have been derived directly from veins intersecting the granite.
If I might venture to offer a suggestion, I would say that instead of a hurried examination of a great extent of country, it would be more satisfactory to make a careful examination of a comparatively small area,—say the basin of the Hutt, the Otaki, or the Manawatu. I would recommend that the upper and lateral branches of these rivers (at some distance from the coast) should be carefully explored, and rough sketch maps made showing the various rock formations,—rough maps which might hereafter be amended, revised, and in some parts wholly altered as discoveries would from time to time, be made. The recent drifts filling the valleys of the small tributaries, should be carefully examined down to the bed rock, and the whole depth of each section washed very carefully. One or two careful examinations of this kind would in fact be the very best kind of “Prospecting.” I would suggest just such examinations as Mr. Stutchbury made in New South Wales, and exactly such maps as he constructed.
I do not think explorations very near the coast will be productive of useful results. If we look to the rivers in Victoria we gather some useful hints for the gold prospector. Near the coast the sands of these rivers are almost invariably so poor in gold that they may be said practically to be non-auriferous. For many miles the Yarrowee is nonauriferous, and quite at its sources we have the Ballaarat Gold Field. The Coliban and Campaspe flow into the Murray through a pastoral country, but their tributaries, miles away from their embouchures, are now supporting large numbers of gold miners. The Loddon is only auriferous near its sources, and the same may be said of the Hopkins, the Wimmera, the Werribee, and every river in the country. A very slight consideration of the facts connected with the occurrence of gold in drifts and recent accumulations will show that the sources of streams, rather than the streams themselves, are most likely to yield the metal in remunerative quantities.
It is probably true that gold is widely disseminated in rocks of the oolitic age, but, according to our present knowledge in such a state of minute subdivision as to be wholly unavailable to the miner. The sludge from a puddling machine contains gold, but the greatest quantity is caught and retained in the box. And so we may consider this operation of nature by which great masses of rock have been worn down and washed as but another kind of puddling, and we must reach the source of that grand agency before we find the gold.
I have not alluded to the modifications likely to be produced in the strata of the drifts and recent tertiaries by glacial action. These should not be overlooked by the gold prospector. Where this force has been exerted gold may be distributed very unequally through the strata, and such rocks may quite puzzle even the experienced gold miner. Though it is true that the specific gravity of gold is sufficient under ordinary circumstances to determine its position on the surface of the bed rock, yet when the gold is imbedded in large fragments of quartz it may be found at all depths from the surface downwards, and in conducting explorations in drifts of this kind all the debris should be carefully examined.
As there are undoubtedly coal bearing rocks in the Province of Wellington no opportunity should be lost of shewing the extent, thickness, dip and general character of these.
R. Brough Smyth.Printed under the Authority of the Government of the Province of Wellington, by Thomas McKenzie and James Muir, Printers for the time being for such Government.
Council Paper.Province of Wellington.
Session XI.Geological Report,By The Hon. J. Coutts Crawford.Printed under the authority of the Government of the Province of Wellington, by Thomas McKenzie and James Muir, Printers for the time being to such Government.Geological Report.
Wellington, January 1, 1864.
To His HonorI. E. Featherston,
Superintendent of the Province of Wellington.Sir,—
Since my report of April 13th, 1863, I have examined the south end of the Island, where it abuts upon Cook's Strait, and have also traversed various points in the Wairarapa and East Coast which I had not previously visited, including an ascent of the Aorangi range.
With the late additions, the traverses which I have made across the line of strike, in the East Coast country, now amount to six in number, and are as follows:
Round the shore from Wangamoana to the East Coast.
From the Huangarua river by Waipawa to Teawaite.
From Te puru puru, across the Wainuioro valley to the head waters of the Kaiwhata and thence to Waikaraka.
The high road from Masterton to Castle Point.
From Knight's station, at the foot of the Puketoi range, by the Tinui line, to the coast at the Whakatake river.
From the Ruataniwha plains to Porangahau, in the Hawke's Bay.
The latter examinations leave little for me to add to the views I have previously expressed, with regard to the East Coast rocks.
I find the old rocks to extend from Cape Palliser, in mass, as far north as the Pahaoa river—to the northward of this river they are only found in patches, overlaid by tertiary rocks, (as, for instance, high up in the Kaiwhata river), if we except a range running from the Huangarua river towards Hurunui orangi, which appears to be formed of old sandstones and slates.
These old rocks, from Cape Palliser northward, appear in general to be identical in lithological character with those of Tararua and Rimutaka, but I am not quite sure of this, for perhaps in some places they assume a different aspect, and the sandstones are also slightly calcareous.
The tertiary rocks, in these districts, fill up the vallies and cover the old rocks partially, or entirely, and it is often difficult to establish the exact line of demarcation.
I have, in a previous report, pointed out the rocks of the East Coast lying between the shore and the line of “taipos,” as of indeterminate age. I regret to say that, although I have found organic remains in them, these are of such faint and indistinct character, that the interesting question of their age must remain still unsettled.
These rocks consist of white limestones, more or less siliceous, in thin strata of from four to six inches thick, but cemented together so as to form a great thickness in the aggregate; they are alternated with sandstones with great regularity; there are also calcareous grits, cherts (probably altered from the calcareous, by the intrusive igneous rocks), sandstones showing carbonaceous markings, shales apparently carbonaceous, and there is also a rock, largely developed, coloured green and red, apparently by chlorite, or by epidote, which assumes every change from an apparent igneous rock to a sandstone.
These rocks may be Palæozoic, but as such they would hardly be likely to be so rich in carbonate of lime as they are; they may be tertiary, but then probably they would show their age by numerous fossils. In classing them as I propose to do I must mention that I am not satisfied as to their position with regard to the old rocks of Cape Palliser; greatly fractured, and dipping in various directions, this is a point difficult to determine.
Under the circumstances I will venture to put them down provisioually as Mezozoic, they are highly inclined and have evidently been forced into their present position by the intrusion of eruptive rocks. In the bed of the Kaiwhata river I found boulders of many varieties of igneous rock; amygdaloidal trap, basalt, hornblende rocks, &c., and at the Waihekino, about six miles south of Flat Point, I found reefs of the intrusive rock “in situ.”
Note.—Containing diallage, or bronzite.—W. B. C.
I have also in the Wai-nui-oro, found boulders of more varieties of igneous rock, including porphyries, to the westward of the line of “taipos,” and at the Kahumengi a boulder of what appears to be trachytic porphyry, containing much iron pyrites.
I wish distinctly to point out that I do not include in the above named group of East Coast rocks, the various decided tertiary rocks that are found there, viz: The sandstones and mudstones with plant impressions, and small seams of brown coal, near Castle Point, &c.; a grey limestone at the slip panel on Mr. Barton's run containing ostrea; the fossiliferous reef at Castle Point, and various other limestones containing tertiary fossils.
I will now offer a few remarks on the newer tertiaries, which occupy the country from the Wairarapa to the “taipo” line (say seven miles from the East Coast.) The fossiliferous limestone which caps many of the ranges on the eastern side of the Wairarapa may be of about the same age as the “drift” gravel. I am inclined to think that in the period of the “drift” the land stood at a level of about 1000 feet below its present height, and that while the wearing away of the older rocks went on, which produced the crystalline sandstone gravel of the Wairarapa, the limestones, which are now at a height of 700 to 800 feet above the sea, might have been formed as reefs at a depth of 200 to 300 feet below the ocean level. I have never found this limestone, nor its underlying rocks; resting on the crystalline sandstone gravel, but there is much gravel derived from tertiary rocks, and soft deposit of mud, or marl, in the district above mentioned (and on which I think the limestone partly rests) frequently obscuring the stratification and almost always covering the “blue clay,” which in consequence, is seldom shown except in vertical sections. The calcareous marls of the hills bounding the Wairarapa on the East may be eventually of great use in fertilising the gravels of the Wairarapa.
The “blue clay,” sandstones and limestones of the above named district, generally dip slightly to the westward, probably tilted by the action of the eruptive rocks on the country towards the East Coast.
Having, as above, stated the result of my late observations on the East Coast rocks, I now propose to consider the Palæzoic rocks by the aid of the light thrown upon them by my old friend the Rev. W. B. Clarke.
In entering upon a geological enquiry as to the age of the rocks of this province, it soon became evident that the great interest centred upon the old and highly inclined rocks of the main range and its outliers, for, whereas the tertiaries which occupy so large an area of our surface are all more or less fossiliferous, and therefore it was a mere matter of time and comparison to ascertain their relative ages with regard to each other, hitherto the old rocks had yielded no organic remains of any description, and we were in consequence, totally ignorant as to their age. At the same time there was a sort of fixed opinion, among these who had considered the subject, and in which view I joined, that these rocks were Silurian, and therefore Graptolites, and other organisms of the Silurian age, were what were sought for.
However, as my enquiries proceeded, instead of characteristic Silurian organisms, impressions of plants were found, indistinct it is true, and without definite character, but still showing the presence of vegetation. I then discovered in many places thin seams of a black, coaly, looking subtance, and, particularly up the Otaki river, thicker seams of the same kind, with some faint impressions of plants, as also anthracitie looking slates. I saw that the “black mineral” looked very like coal, but remembered a dictum I had once heard of Sir Humphrey Davy's, that the primary tests for coal might be thus stated:—“Is it black and does it burn.” Now the black mineral that I had found would not ignite, even under the blow pipe, and the only reaction we could here obtain from was for iron. I was therefore obliged to send specimens to Australia for examination, and to wait for an opinion from that country.
With regard to these specimens, the Rev, W. B. Clarke writes as follows, on September 12th, 1863.
No. 37. Plant beds of Porirua{Like some beds in New South Wales coal field and also in England.No. 40. Sandstone of Waikanae{A coarse quartzoze grit, probably a coal measure rock.No. 54. Wai-o-taueru, Upper Otaki.{Calcareous quartzoze rock of the carboniferous formation. The black substance is coaly.No. 55, Gorge of Ruamahunga and 56. Wai-o-taueru, Otaki River.{Unmistakeable portions of a coal seam with coal. Similar patches of coal occur in the N.S.W. beds, where the coaly matter is traversed by lime threads. I consider this old, and perhaps the coal passes to anthracite.No. 65. Oriental Bay.{Shale and sandstone of igneous materials from coal bed of same age, as No. 37, Porirua.No, 69. Otaki river.—An altered rock of the coal beds.
“The occurrence of beds composed of what were once igneous materials, but since transmuted, are extremely common in the N.S.W. coal fields. Porphyritic grits; and fine conglomerates of almost granitic compounds are equally common. Near Scone, in the Upper Hunter district, such occur in Fig-tree Gully. At Prospect, in county Cumberland, and about Glen Alpin, near Campbeltown, and on the Paterson, rocks of this kind are very common, also in Illawarra there are like products.”
“The black substance which I examined before, illustrated by the new specimens, is quite in accordance with a substance of like kind near Wollongoug, which was reported to the Government here as graphite. It is from a bed of shale in the Mount Keera seams. On the whole, I consider this lot of specimens to justify the expectation of coal at the S.W. corner of the Province.”
The conclusion to be drawn from this report is, that the whole series of the rocks of these mountain ranges, with the exception of certain igneous rocks to be treated of in another place, may be “carboniferous,” From the plant beds of Porirua to those of Oriental Bay, from the “carboniferous” (?) grit of Waikanae to the black seams of the Rimutaka and the Wai-o-hine, from the coaly seams and the anthracitic looking slates of the Upper Otaki, to those of the gorge of the Ruamahunga, the report is constantly “carboniferous,” and from the number of different points at which the indications are found, we must, I believe include the whole of these rocks in one group, a most important point to establish.
It will be perceived by and bye that the evidence, in favour of a “carboniferous” age must be modified; but I prefer to let the report stand unaltered, (even although it may appear somewhat contradictory), to show how necessary a careful chemical examination may be, to enable an observer to draw correct conclusions.
I had, in a previous report, adopted the view or the learned Professor McCoy, of Melbourne, that the plant beds of Porirua were of Mezozoic age, and was willing to suppose that they rested upon older rocks, but now that we are forced to class all the old rocks together, I must demnr to the Mezozoic view. At all events until the discovery of distinctive fossils, I shall class all these rocks as Palæozoic; from their position, and from their connection with the Eastern ranges of the Middle Island, I cannot do otherwise than describe them as such.
The plant impressions of Porirua and of Oriental Bay appear to be of marine origin, which perhaps increases the probability of a Silurian age for these rocks; but some of the organisms would appear to be terrestrial, or, at all events, semi-aquatic plants.
Certain fossils will be found described further on.
Having now arrived at the fact that our old rocks are carbonaceous in character, and possibly of “carboniferous” age, it remains to be seen what chances there are of finding workable coal seams amongst them.
Looking at the high inclination of the strata, and bearing in mind that we have hitherto been unsuccessful in finding coal seams of any consequence in traversing numerous sections across the line of strike, one would be inclined to decide this question in the negative; but there are reasons why we should not arrive at this conclusion too hastily.
In the first place, even in the line of the most exposed sections, there are large spaces covered by debris, or by forest, or otherwise so hidden from view that their strata cannot be spoken of with confidence. At the highest point, for instance, which I reached on the Wai-o-taueru, which falls into the Upper Otaki, the evidences of coal, or of carbonaceous substances, became very numerous, but here the cliffs of vertical strata, through which the river had hitherto cut its bed ceased, and the river ran over beulders, presenting no sections. In the ascent of the snowy range from this point no rock was found, except a few fragments thrown up in the roots of fallen trees.
Towards the centre of the range therefore, as elsewhere, coal seams may exist, but I believe that if they do, they are beyond the reach of the geological hammer, and will require a search with the pickaxe and spade.
It may be doubtful whether or not coal found vertical, or nearly so, would be of any practical value, but perhaps the first consideration should be to find the seams, the next to consider whether they can be worked.
If, however, all the carbonaceous seams, or veins, prove to be graphite instead of coal, the probabilities are that our old rocks are “Silurian,” or perhaps “Devonian,” and then, of course, a search for coal could not prove successful.
Before concluding my remarks on the Palæozoic rocks, I would observe, that in the great longitudinal valleys, such as those of the Hutt, the rivers appear to run in the line of the anticlinal “axes,'
Note.—From the broken character of the strata, a true line of axis is difficult to determine.
whereas in the lateral valleys on both sides of the range, the river beds occupy mere cracks across the line of strike and may be said to have no true valleys while within the mountains, with the exception of a few inconsiderable terraces. In the place of valleys, there are mere ravines.
Note.—Dr. Haast makes particular mention of the beds of the Western rivers of Canterbury occupying anticlinal “axes.”
Gold.
It will be remembered in my previous reports, that with the exception of finding gold beneath the tertiaries of the westward of the Province, I had reduced the districts in which gold might be found, to the inclined rocks of the main range of Rimutaka, Tararua, and Ruahine, and its outliers at Cape Palliser and the Kaimanawa range, and to the “drift” derived from them.
Now that we have some slight evidence as to the age of these rocks, it remains to consider its bearing upon the gold question.
The highest authority in these matters, Sir R. Murchison, lays down as follows:—
“Appealing to the structure of the different mountains, which at former periods have afforded or still afford any notable amount of gold, we find in all a general agreement. Whether referring to past history, we cast our eyes to the countries watered by the sources of the Golden Tagus, to the Phrygia and Thrace of the Greeks and Romans, to the Bohemia of the middle ages, to tracts in Britain which were worked in old times, and are now either abandoned or very slightly productive, or to those chains in America and Australia, which, previously unsearched, have, in our times, proved so rich, we invariably find the same constants in nature. In all these lands gold has been imparted abundantly to the ancient rocks only, whose order and succession we have traced, or their associated eruptive rocks. The most usual original position of the metal is in quartzoje veinstones that traverse altered, Palæozoic slates, frequently near their junction with eruptive rocks. Sometimes, however, it is also shown to be diffused through the body of such rocks, whether of igneous or of aqueous origin. The stratified rocks of the highest antiquity, such as the oldest gniess and quartz rocks (like those for example of Scandinavia and the northern Highlands of Scotland), have very seldom borne gold; but the sedimentary accumulations which followed, or the Silurian, Devonian, and Carboniferous, (particularly the first of these three) have been the deposits which, in the tracts where they have undergone a metamorphosis or change of structure by the influence of igneous agency, or other causes, have been the chief sources whence gold has been derived.”
You will perceive from the above quotation that, supposing our old rocks to be even as high in the scale as Carboniferous, Sir Roderick holds out a hope of finding gold in them.
I may give a still more favourable opinion on the authority of Mr Jukes, whose work on geology is perhaps the most useful and practical manual extant on the science. He states,—
“The supposed relation between mineral veins and the age of the rocks they traverse is probably an accidental one only. Mineral veins may be expected in all highly indurated and greatly fractured rocks, whatever may be their geological date. Neither
does the connection between mineral veins and the occurrence of igneous rocks appear to be better founded, than on the probability that igneous rocks will be most likely to be found in the same indurated and fractured districts which we have seen to be essential for the production of mineral veins.”
Having thus, on the authorities of Sir R. Murchison and of Mr Jukes, shewn that there was a prima facie case for the search for gold in our old rocks, I will proceed to point out why we need not expect alluvial or “drift” diggings among them, and will then consider the chances of finding gold in the rock itself.
The main reason why we need not expect to find gold diggings in, or derived from, our Palæozoic rocks, is simply from the result of experiment.
As in careful washings of the gravels of the Hutt, the Wai-o-hine, the Ruamahunga, and the Otaki, (performed under my inspection in March last), no trace of gold was found, it would seem absurd to expect any payable “diggings” within the same ranges of mountains which are traversed by these rivers.
Next, although Sir Roderick Murchison includes the Devonian and Carboniferous groups within those in which gold may be found; yet, practically, no payable gold has been worked, at all events in the Southern Hemisphere, that is not in, or has not been derived from Silurian rocks, perhaps I may say from lower Silurian only; and if our rocks should prove to be higher in the scale than these, our chances of workable gold are reduced.
It is however certain that the rocks in the immediate vicinity of Wellington contain some gold, although hitherto not found in payable quantity. I need hardly instance that found at Terawiti.
As it appeared a difficult point to decide whence the little gold there obtained in the gravel was derived, I took advantage of a similar discovery on the Karori road, close to this town, to send some of the underlying rock to Sydney for analysis, and have received the following report from the Sydney Mint, shewing that there is some gold in the rock itself.
“Assay for Gold of three samples of rock received from Rev. W. B. Clarke.
“These samples all bore the No. 68.”
“The first sample tried, being the softest and lightest colored, contained a minute trace of gold, but not exceeding a few grains to the ton.”
“Second sample tried contained no. gold.”
“Third sample tried contained no gold.”
I am also informed by Mr. Brough Smyth that he detected gold in a specimen of quartz forwarded by me to Melbourne—locality not stated by him.
These results are not encouraging, but still they tempt to further investigation. As the indications of gold are principally in the immediate vicinity of Wellington itself, enquiry is comparatively easy; the rocks are ready of access and tolerably soft, and a small per centage of gold might yield a profitable return.
What is wanted for this enquiry is not a “prospector,” but a good analytical chemist, assisted by a competent miner. In this investigation no powerful quartz lodes need be expected, but sundry rocks will be found seamed with thin quartz veins, and it is just possible that these rocks may contain a notable quantity of gold diffused through them. Towards the central part of the range, the rocks that are in sight, are less crystalline, and less likely for gold than those nearer Wellington.
I have before pointed out that the grand gold bearing rocks of the Middle Island are the micaceous schists lying to the westward of the Eastern ranges; and I must again repeat, that, considering the general parallelism of the old rocks of New Zealand, analogy would lead one to expect to find the gold rocks, the above mentioned mica schists, towards the west of the Province, where, however, on account of the great thickness of tertiaries, it is impossible to determine, without sinking, what may lie beneath. I would not however advise a neglect of the few gold indications of the Eastern ranges, but, I consider a chemical investigation, as above recommended, ought finally to exhaust the subject.
Igneous Rocks.
True igneous rocks occupy but a small portion of the surface of the Province, but the more one investigates, the more one finds the eruptive rocks exposed in the great fractures, and sees in the jasperoid rocks the evidence of their action.
A red rock of Rimutaka, which I consented to put down as a lava, is now decided by the Rev. W. B. Clarke, to be a jasperoid rock. The supposed granitic character of a rock of the Upper Hutt, must, I believe, also be abandoned.
The igneous rocks of the Province may be classed in two grand groups.
The volcanic rocks of the central chain of Ruapehu and Tongariro.The eruptive rocks of Rimutaka, Tararua, and of the East Coast.
Looking at the geological sections of the Province, these igneous rocks at once strike one as forming a grand series of ribs and buttresses, which lock up and support the sedimentary rocks and the North Island.
In the centre, the grand volcanic chain of Ruapehu and Tongariro rising from an elevated plateau to a great altitude, forms the great striking feature of the landscape.
Turning now to the eruptive rucks, I believe we must look to Tapuanuka, the inland Kaikoura, as their chief centre of action, whence slightly divergent ribs have been sent.
Up the East Coast of this Province penetrating and tilting the sedimentary rocks in that direction.To the Muka-muka rocks and thence to the N.N.E., changing the overlying sedimentary into jasperoid rocks.Towards Sinclair Head and thence to N.N.E., with a somewhat similar result.
The intervention of the Strait does not militate against this view. The Strait would seem to be a zone of “fault” and submergence.
Those who consider that the deep sounding in Palliser Bay, where the depth changes suddenly from 74 fathoms to 142 fathoms (no bottom), shows the site of a submarine crater, may probably look upon that point as the focus of present action, but, I would suggest that a submarine crater ought to show shallow instead of deep soundings, that the soundings would also indicate the outward slope of a crater, which they do not do, and that there is really no evidence to show, that any earthquake phenomena originated from that place as a centre.
Note.—It may appear that I am mixing up together old and new igneous action. I do not positively know when the first intrusion of eruptive rocks occurred; but, whenever that action may have commenced, it has probably continued until now.
It is true that after the earthquake of 1855, dead fish and a bituminous substance, were washed up on the coast near Wellington, shewing that volcanic action in the Strait had been attended with the emission of gases, or lava, or noxious products of some kind, but the evidence that this action occurred, in particular, at the deep sounding in Palliser Bay, amounts to nothing.
To consider fully the igneous phenomena, one ought, however, to be acquainted with, and to include the whole of the igneous rocks of the North Island, As I have, however, no right to travel beyond my own “Province” in this enquiry, I will merely indicate that the principal seat of the volcanic rocks of New Zealand lies in the Province of Auckland, that Taranaki has its one volcanic cone, and that Hawkes Bay possesses no igneous rocks “in situ,”
It has plenty of deposited pumice, however, brought down from Tongario.
that I am aware of.
Although a thorough investigation of the volcanic rocks, with a view of escablishing at what geological period their action commenced, would occupy far more time than has been at my disposal, I will state, as a starting point for future enquiry, that the eruptions of the great central chain appear to me to have begun after the era of the “blue clay,” possibly intermediate between the older and newer sedimentary tertiuries.
I have not found igneous boulders in the “blue clay,” while they are common in the overlying rocks In connection with this question the sedimentary tertiaries of the West Coast would require a very careful and detailed examinination, which would occupy a good deal of time. Slickensides occur frequently in our old rocks.
Terraces and Raised Beaches.
Terraces and raised beaches are a very prominent feature in the Geology in this Province.
It appears to me that during the “drift” period, this Province and perhaps the whole of the North Island, stood at a level of 1000 feet, a little more or less, below its present height.
At about 1000 feet, gravel terraces are found,
Possibly several hundred feet higher may be included.
and also at about 400. 150 to 200, 15 and 4 to 9 feet. Between many of these larger terraces, smaller ones may be perceived.
That these terraces generally mark successive rises of the land is probable, although the evidence of fossils is in general wanting
Note.—There appear to be some “drift” fossils at Rangitikei.
(and this may indicate a glacial origin, for many of the terraces instead). I have, however, seen in the Wairarapa one terrace at least, which in a few years will be indistinguishable from the others, and which was caused by a “fault” during the earthquake of 1855.
At Terawiti, Oriental Bay, and elsewhere round the coast, there is evidence of a very marked sea beach, waterworn, and the rocks bored by pholas, at about 15 feet above the present high water mark. It seems almost superfluous to mention the marks of the well known rise of the land in 1855, of from 4 to 9 feet.
At the time of the deposition of the “drift” gravel, the tertiary basin of the West Coast, must have presented a series of unbroken, level, or slightly inclined terraces, beneath the sea, otherwise, the narrow valleys which now exist, would have been filled up by the “drift” in angular deposits.
The “drift” of the Mungarua hill, and others of similar character, probably mark the sites of ancient glaciers.
Within the limits of Wellington itself, there are considerable deposits of gravels and clays resting on the old rocks and containing plant impressions. At Burnham Water there are strata of gravel and sand, containing struthiolaria, ostrea, pecten, turritella, &c., at a height of about 10 feet above high water mark, and also beds of peat covered by sand, and at Makara there is a fossiliferous patch, probably marking an old sea beach. All these would appear to be “recent.”
Since writing the above I have received Mr. W. B. Clarke's report of January 5th, 1864, of which I enclose a copy, not only to show the progress of the argument as to the age of our Palæozoic rocks and the difficulties which surround the question, but also to point out to you and to the inhabitants of Wellington, how much trouble Mr. Clarke has taken, and how much interest he has shewn, in the advancement of the knowledge of the geology of our province, and, I may state, that this report only embodies a small part of the work which he has performed, for I have been in constant correspondence with him ever since the commencement of the geological survey, and have received from him the most steady and zealous assistance.
My first impression was, on reading this last report, that I should have to modify and alter all that I had written previously concerning the Palæozoic rocks; but, on second thoughts, I have decided to leave my original report with a few alterations only, and to add a few observations on Mr. Clarke's views, as expressed in this last communication. As the argument as to the age of our old rocks will probably sway backwards and forwards for some time to come, until more distinctive fossils are found, I believe this plan will be most conducive to show what results have been arrived at, and how we have reached them.
The main points to be determined by me after a consideration of Mr. Clarke's last report, are as follows:—
Does our main range consist of one group of rocks only, or of more than one?Of what age are these rocks, whether of one or more groups?
In reply to this, I consider that Mr. Clarke's previous decision, in which he establishes the carbonaceous character of the rocks at a great variety of points, is almost conclusive as to these ranges consisting of one group only. I have already stated my views on this head and also with regard to the supposed Mezozoic rocks and therefore I need not repeat them. I can see no appearance of unconformability among the old rocks, they seem to be all equally thrown up at high angles, but the numerous dislocations, bends, and faults render it difficult to speak with certainty and I will not deny the possibility of there being two groups of rocks within the ranges.
The supposed Phyllotheca of Porirua, as also the Theca, or Dentalium of Belmont, may soon assist us to resolve this question.
With regard to age, although I have been tempted in the direction of the Carboniferous, yet, I must now confess, that the balance of evidence is in favour of older rocks. The supposed coal has appeared all to resolve itself into graphite, for even No. 55, from the Ruamahunga gorge, which has a strong appearance of coaly structure, I know positively will not burn, and will probably prove to be a graphite like the rest.
The relation of similar graphite to the auriferous lodes of “St. Arnaud” may perhaps tempt to further careful examinations in such places as the Otaki river, where the “black mineral” is in abundance.
Mr. Clarke's theory as to the deposition of the graphite from water is a probable view, in some cases at least, for there are reasons to suppose that hot springs have played a considerable part, both in the main range and on the East Coast; but we must also consider that the “plant beds” of Porirua and of Oriental Bay, and also some obscure impressions on the Otaki river, show the presence of plants, which appear to have been imbedded in the usual manner and therefore the carbon there was not derived from infiltration.
It may appear that the result arrived at as to the age of our Palæozoic rocks is still very indefinite and that I might have been prepared with a more direct statement; but, if you consider the evidence which is now before us, you will draw the inference that our difficulties have probably arisen from the transmuted character of the rocks, and the consequent destruction of distinctive fossils.
This difficulty may permanently prevent our arriving at any definite result, but, as I have been able to find some organisms, however obscure, which help to show in what direction to search, there is every reason to hope, that as the country is opened, and the rocks broken into for road-making and other purposes, characteristic fossils will be brought to light.
To be enabled step by step to gain a correct knowledge of the age of our rocks, it is almost essential that we should have a properly regulated Museum, under a Curator, otherwise comparison is impossible, the results of observations are lost, and each fresh enquirer has to begin anew.
In connection with the argument as to the granitic character of the rock, marked No. 3, Upper Hutt, I subjoin a list of the specific gravities of some of our rocks as weighed by me, warning you, at the same time, that I was not in the possession of a balance of great nicety.
Catalogue of Specific Gravities.
Slate near Featherston2.77Slate near Featherston2.63Ferruginous quartz, Waikanae2.7Quartz, Mungaroa hill2.4Quartz, Mungaroa hill2.55Serpentinous Slate, Otaki2.73Quartz, Pitoni road2.62Jasperoid Rock, Rimutaka2.71Sandstone, of Waikanae2.52Soft Clay Stone, Mungaroa2.22Soft Clay Stone, Belmont Hill2.29Carbonaceous Rock, Porirua2.45Serpentine, Mungaroa hill2.73Green effeiveseent pyritous rock, Petoni road2.61
The above list would seem to show that the disputed granite (No. 3) is of no greater specific gravity than so no other rocks of the range; consequently the argumenent founded on the specific gravity is weakened.
You will perceive that Mr. Clarke recommends a trial for gold in the trap of Waihekino,
Six miles South of Flat Point.
which contains diallage, or bronzite.
I cannot say that I have any faith in Gold being found in this rock in payable quantity, but undoubtedly it should be tried. “Diggings” need not be expected in its neighbourhood, if the diallage contains Gold it will be in a state of extreme fineness.
This rock of Waihekino traverses calcareous rocks which I suppose to be “sacondary,” and if I am right in this view the chances for gold are not encouraging.
I must again refer to another Province for an illustration of a phenomenon which may be observed in a lesser degree in the Province of Wellington, particularly in the neighbourhood of Whanganui.
Since I have framed this report I have visited the Waikato country, and I there see unmistakeable evidence of an era during which the central volcanoes have emitted an enormous quantity of pumice and volcanic ashes, which, on being washed down from the interior, have covered up the country to a considerable depth, burying and destroying an ancient forest.
I have some reasons for supposing that this era was one of submergence, but those which I can perceive against this view are more cogent, and I think the action of rain and rivers sufficient to account for the distribution of the materials.
Indeed, as pumice floats in water, it would be difficult to show how it could be deposited from the sea at all, unless heaped up upon the shore.
I may also state that my observations in the Waikato lead me to suppose it probable, that the tertiary coal field of Whanganui is a continuation of that of the former district, although, I am bound to say, the associated rocks do not appear, on a cursory view, to bear the same lithological character.
During last winter I made drawings of all the tertiary fossils which I had collected, with an expectation of having their species determined in time for this report.
This however I have not been able to get accomplished, but I hope to receive information, concerning them, which I may forward to you at a future time.
Dr. Haast informs me that Zittel has divided the New Zealand tertiaries into two main sub-divisions.
I suppose both of these to be represented in the Province of Wellington, but until I have been informed as to the species of our fossils, it would be premature to lay down definite conclusions; the large cucullæa however, associated with the “Blue clay,” appears to indicate the older tertiaries, overlying the brown coal beds; while the more recent tertiary beds are largely developed on both sides of the Province.
Mr. Clarke has forwarded all my Palæozoic organisms, or supposed organisms, to England, for examination, so that by and bye we may hear of them again.
In conclusion, I think I may claim to have advanced the knowledge of our rocks, as far as could have been expected, considering the obscurity which previously hung over them, and the scarcity of fossils. I also think it may be shown that I have saved the Province some outlay, both in what it must have paid for an imported Geologist, and in avoiding the employment of a “Staff,” when it could not have been satisfactorily made use of.
I have to thank you and the Provincial Council of Wellington for your support in a highly interesting investigation.
I have to thank my old friend, the Rev. W. B. Clarke, for the very great trouble which he has taken in assisting me, and for which the Province also should be grateful.
From Dr. Julius Haast, the Government Geologist to the Canterbury Province, I have always received prompt and intelligent assistance, and he has now kindly undertaken to watch the progress of the lithographing of the Geological map of the Province, at Christchurch. My thanks are also due to Mr. Brough Smyth, Secretary to the Mining Department at Melbourne, and from Dr. Lauder Lindsay, I have received valuable information.
Last, but not least, Mr. Walter Mantell's services were always at my disposal, for the investigation of minerals, or for the determination of fossils.
I have the honor to be, Sir,Your most obedient servant,James C. Crawford,
Government Geologist, Province of Wellington.
In connexion with the proposed New Zealand Exhibition, to be held at Dunedio next year, I would suggest that blocks of sufficient size of the following named rocks should be collected and prepared for transmission to it, with the view of obtaining an opinion as to their qualities as building or ornamental stones, &c., viz.:—
Stone.Locality.Purpose.1. LimestoneWhite Rock, Pahaoa, &c. East CoastLime, Building Stone, Cement.2. SandstonesDo. Do.Building Stone3. SandstoneFront Range WaikanaeDo. Do.4. Hard Crystalline SandstonesHarbour District, Makara, &cDo. Do.5. Eruptive.Muka Muka, Makara, &c.Do. Do.6. Jaspers and Jasperoid rocksMuka Muka, Rimutaka Road, &c.Ornamental (try to polish)7. Tertiary Sandstones and Calcareous SandstonesUpper Whanganui RiverBuilding Stones8. Veins of Carbonate of Lime Septaria, Strata of Shells and SandEast Coast, Wairarapa, Whanganui RiverLime and Cement
N.B.—Pumice is said to be an excellent ingredient in making cement, and there is an inexhaustible quantity of it in the Whanganui river.
It might be worth while to have searched for, and polishe, some of the pebbles of the East Coast.
Were not the traps and lavas of the volcanic chain situated in a district so difficult of access, I should recommend that specimens of them should also be procured.
It might also be possible to obtain good samples of the brown coals of the Whanganui and its tributaries.
“Copy of Letter of Rev. W. B. Clarke“St. Leonards, Sydney, January 5th, 1864.My Dear Mr. Crawford,
“Your last parcel did not reach me till some days after the mail started again. What with that and the delay in working up the “black stuff,” respecting which I did not like to report finally, till I had laid my views before two excellent mineral analysis, one in Victoria and the other at the Mint here, you have I fear waited with some im patience from week to week. But this sort of work takes time, and halt work is none.
“Revolving your map as you have explained it and taking the section from W to E. into consideration, I see no help for the fate of the disputed rocks but this. Either the main ranges are of one, or of more than one epoch. If the latter, how are we, on the supposition of an independent coal formation, to account for the occurrence of the carbonaceous beds on both sides of the anticlinal of Tararua, with parallel strike and dips; and would not any coal formation be unconformable
Not necessarily unconformable.—J.C.C.
to the other rocks if they are older? You have plenty of evidence as to the existence of igneous rocks, of probably, several ages in that chain. You give prominence to jasperoid masses which testify to transmutation. My notes on the specimens show that there have been dislocation and upheaval. Then you have, certainly, evidence of the intrusion at some time or another of porphyry. In all these respects but the strike and dip, I see a great conformity with the Eastern side of Haast's great fissure in Nelson; and the ranges there may agree with yours.
They do not, but lie to the westward of ours.—J.C.C.
But Hochstetter has an idea of a shifting of these ranges to the eastward in Wellington and Auckland. Could your ranges be really different from those in the Middle Island; i.e., more to the east, and covered or only occasionally appearing in Canterbury? I have laid down your colouring on the small map of Petermann, and it looks as if your Rimutaka ranges crossed to Cape Campbell, and the Aorangi ranges struck out for the Christchurch country;
The continuation of the whole breadth of our ranges from Terawiti to Cape Palliser, may easily be traced across the Strait and carried South until the corresponding rocks are found skirting the Canterbury Plains. A graceful curve must be allowed, not a rigid straight line. There is no necessity to suppose a lateral shift.—J.C.C.
in which case the Nelson ranges would appear again on the east side of Taupo Lake, where you have a patch of a similar formation. If this is the case all your formation in the heart of the ranges may be of different general age to the West Nelson country; and therefore we need not look to that for comparison. Nevertheless, there are in some of your younger igneous rocks resemblances to some of Haast's. But then again where are the well developed secondary rocks which undoubtedly exist in Nelson, if not in Canterbury? All you have are the patches of vegetable tissue in the plant beds and the Theca?
The fossil is evidently crushed, but it shows an irregular kind of opening at the upper end. It is, however, arched like Dentalium, though slightly I do not see the slit at the lower end which usually occurs in Dentalium. It is nevertheless apparently open at both ends, as in Dentalium.
or Dentalium in No. 39, for I have seen no other fossil in any of your collections.
I have not sent any tertiary rocks or fossils to Mr. Clarke. Our secondary rocks to the westward are either wanting, or they lie below the tertiaries. To the Eastward see my remarks on East Coast.—J.C.C.
The supposed graphite would naturally point to old Silurian rocks rather than to young secondary, or upper Palæozoic. But whether they are lower or upper does not appear. The Makara rocks look marvellously like upper Silurian.
Note—You should search Belmont for fossils.
In that case you will have probably very little gold; and as certainly no regular coal formation, though the carbonaceous matter is quite in agreement with experience.
“I think you will have to find out by further researches to the N.E. whether the formations are one or several, and if there is any unconformable deposit over the vertical beds, of a coal age.
This is just what I have been unable to find, unless the Porirua beds should prove to be such, but Belmont is about in their line of strike, and the Theca? or Dentalium there conflicts with the Phyllotheca? of Porirua.—J.C.C.
“I wish I could enlighten you thereon, but at present you have sent me nothing which agrees altogether with our coal formation here, except as I have before mentioned. My idea once was that coal beds might exist on your West Coast, but the study of your map shows me, that if so, they underlie the tertiaries.
“I learnt lately that the Whangaroa and Aotea tertiaries on your West Coast (i.e., of North Island) are perhaps Eocene like those of Cape Farewell in the Middle Island and about the Waikato. The younger, or sub-appennine beds, occur in your Island about the N. of Auckland, Whanganui, Hawke's Bay and in the Middle Island about Nelson, &c.
“I always believed that the order was from E. to W. in point of age, and Haast tells me Zittel's views confirm that idea. The elevation of the islands has gone on from W. to E. as Haast shows,
I do not quite understand this, and therefore I may be wrong in thinking it erroneous.—J.C.C.
which quite agrees with the tertiary arrangement. He says further that he is obliged to include among the Eocene tertiaries some deposits which Hochstetter and others considered Cretaceous.
“Believe me,
“Yours very truly,(Signed) “W. B. Clarke.”
Catalogue.
Upper Hutt (Granite?)
No. 3. I can find no waterworn particle in this rock, and I have very carefully examined all the specimens with various microsopic powers in that view. The appearance of the rock is that of dykes or veins which often traverse granite, and to one of these I referred it at first. That it is bedded, I doubt, but it is jointed in several places and traversed by threads of segregated matter, parallel with one or other of them. Its chief elements are crystalline particles of felspar, with some minute traces of glassy felspar, quartz, sometimes crystalline, sometimes basic, with but little mica in proportion to the other, and that is silvery. There are also small points which look like hornblende. I am quite satisfied in my own mind that it is an igneous rock, putting on the character of euritic granite. Dr. Haast mentions a sedimentary rock, which has been taken for granite in the Eastern part of the Western mountains of the Nelson Province, and he satisfied himself it was so after much research. But he must in that case have found unmistakeable proofs of sedimentary origin; there is not one single waterworn particle that I can detect: if you can find any that will leave the rock under the head of hardened, regenerated, granitic detritus,
Note.—After a further examination I believe we must accept this latter alternative.—J.C.C.
but such detritus would betray its secondary composition. The rock is much decomposed though very hard.
P.S.—As a further test I have to-day (6th January), taken the Specific Gravity which comes out 2.70. Now compare this with the following hard rocks and you will see its character.
Baked white grit, columnar, compact, Bondi, N.S.W.2.37By W. B. ClarkeBaked white grit, columnar, compact, Wattle Swamp2.45Baked white grit, columnar, compact, Pyrmont Stone2.331
Baked cherty columnar sandstone, Sturt's Creek, brought by Gregory, N.W. Australia2.338Granite2.73MeanBy Professor Haughton.2.602.66Syenite2.752.682,63
Piloni Road, Otaki River, Rimutaka, Terawiti, Wai-nui-o-mata, Otaki River.
Nos. 42. 44, 54, 52, 72, 81, 87. These rocks are partly siliceous, partly calcareous, or slaty with quartz and lime, and have very much the appearance of the walls of mineral veins.
They are all more or less covered, or interlaminated, or mixed up with a black mineral which puts on either a powdery sooty aspect, or a compact hard glossy one, (not improbably the result of friction like black lead polish) especially on the surface. No 54 is covered with it in such a way as to lead to an idea that the mineral was sometimes spread by water over broken surfaces of the calcareous rock. This remark also applies to No. 72, One of No. 42 looks more like a carbonaceous shale.
No. 52 shows the substance diffused between all the cracks in the rock. So in No. 81 one of these specimens is a quartz vein so covered. Another of No. 42 do. Another of No. 81 exhibits marks like those of slickensides, indicating motions of surfaces against each other, and the substance in question shows in places (in the harder varieties as in those of No. 54), just such markings as are found under like conditions, as if it had infilled the hollows of a scratched rock, or had contracted on drying and hardening. Again in No. 42, we find patches of iron ochre in combination with the black mineral, as if a ferruginous spring had coated it. In No. 87, the thin surfaces of the plates and joints of a black slate or shale are likewise coated by a shining black wash of the same.
Now with rocks of lime, silica, and alumina, all equally coated and
apparently under similar circumstances and in different localities, it is almost self-evident, that these rocks have been affected by dislocation and grinding and into their fissures and hollows, some of this black mineral has been, as it were, poured or deposited from water. The harder substances bear thicker deposits, as the matter could not get within, but in the softer calcareous veins and shales, there was a kind of percolation and saturation,
Now what is this substance?
Note.—The carbonacerous matter in the thick shining crust amounts to about 2.3 per cent. As tihe Specific Gravity is very high 2.8, and the hardness of that portion about 5, it is quite a new combnation.
There is not a trace of Manganese Its composition is silicate of alumina, hydrated iron carbonaceous matter, and a trace of lime.
Whether the carbonaceous matter has been derived from water passing through coal is doubtful, much of the stuff is like coal, soot, or smut, as you will perceive if you examine the water after washing it. But the composition above given, which has been carefully arrived at, is not so much that of ordinary coal, as that of a kind of Graphite, which you know is a mineral (though related to coal in some way) more transmuted than anthracite, and is chiefly confined to rocks much older than those of the coal formation
N,B.—Professor Rogers has shewn that the Anthracites of the Appalachian chain lie at the bottom of the coal series, just where the igneous rocks would prouce the necessary metamorphic action.
Earthy graphite is by no means uncommon in the Southern Hemisphere, and there are abundant proofs of the existence of carbonaceous matter in the Silurian formation.
I have received a mineral not unlike some portions of yours, from Tasmania and have found it in New South Wales, and in my collections from New Caledonia, I am able also to tell you that this very substance, though softer, and occasionally with minute traces of copper, is found coating the sides of the auriferous and argentiferous veins of “St. Arnaud” in Victoria, as I am informed by Mr. Ulrich, of the Geological Survey of that Colony, who has sent me a sample of it, of which I include a few particles.
With these slight aids, perhaps you may be able to detect the relation of this mineral with the older Palæozoic rocks of your Province, if not with any independent system of coal beds. Whatever may be the result, I am bound to say that in the collection now before me, I see not more than the resemblance I have already mentioned to beds of coal or to the rocks usually associated with such. To these remarks belongs the examination of the next specimen.
Teawaiti.
No. 97.
It is doubtful whether this rock belongs to the main group of the Palæozoic rocks.—J. C. C.
A fine sedimentary highly calcareous rock (calcareous sandstone) of grey colour, and chiefly silicious origin, coated and patched with carbonaceous matter of similar kind. N.B.—I do not forget that a speci-
Ruamahunga Gorge.
55 men No. 55, Ruamahunga gorge, on a former occasion, exhibited what I cannot help thinking is a trace of coal altered so as to wear the appearance of anthracite, or graphite, some portions exhibiting interlaminations of our present mineral, which may therefore really be connected with coal of some age or other.]
In the Porirua plant beds you frequently see the same.
The general conclusion must be, that however derived, the carbonaceous substances with the rocks holding them have been highly transmuted, an opinion confirmed by the existence of jasperoid and cherty, as well as hardened limestone rocks in the midst of these ranges. This is further confirmed by the undoubted evidences new produced of direct igneous action.
Porirua.
No. 37. The cast of a portion of the plant in this specimen resembles very much the stem of Phyllotheca, but it may be that of a fern. If the former it would bring the deposit near to one of our New South Wales beds in the coal series, probably the upper. Dr. Hector writes me word, that he recognized on the West Coast, Otago Province, beds very similar to those of Western Port in Victoria, which I consider equivalent to our upper coal beds. There is something very like your plant beds not far from Port de France, where the Mezozoic rocks lie at the base of the great serpentine ranges.
Belmont.
No. 39. Apparently an upper Silurian rock with Dentalium, or Theca, and cast of worm track, as in the May Hill sandstone of Heidelberg in Victoria.
N.B.—Theca belongs both to Carboniferous and Silurian formations. Dentalium goes as low as Carboniferous.
Hill between Tinui and Castle Point.
Probably epidosite
Ko a rai tea, Otaki River.
Eklogite,—Not a true granite. (This is certainly not in situ, W.B.C.)
Most certainly it is.—J.C.C.
Top ridge of Tararua.
Would have been called greywacke some years ago. It contains felspar and mica, with quartz veins.
Makara.
Felspathic trap. It is probably a porphyritic greenstone.
Karori.
Tabular quartz with iron. There is abundance of this on the Hanging Rock Gold Fields, N. S. W. It occurs close to serpentine. I believe it to be the result of hot springs.
Muka Muka.
Highly calcareous trap. May be an altered ash. The imbedded crystals are too small to test.
Muka Muka.
Iron pyrites in a trap, or metamorphic state. Character of rock indistinct.
South of Flat Point.
Diallage or Bronzite in calcareous greenstone, full of iron pyrites, and not impossible with gold in minute quantity. (By all means get enough of this to test.)
Rimutaka.
Trap.
Kahumengi, East Coast.
Boulder of Trachytic Porphery, containing much iron pyrites
Additional Notes on the Graphite from Van Dieman's Land.
Pure Plumbago consists of:—
Carbon.Iron.90.9 × 9.1. = 100. (According to Berthollett)Graphite of Plusier:—Carb. 23 }Iron 2 }100Al. 37 }Si. 38 }
Now, if Al. and Si. be considered impurities the proportion of Carb. to Ir. will be 91.3 to 8.7, a curious relation. I believe this specimen contains much less. 98 grains of it were burned for 6 or 7 hours, so that nearly all the carbon was destroyed. It then weighed 89 gr.
The mineral contained, Carb.9.081Iron, Alb. and Si.90.919
Some of the burned mineral was macerated in diluted sulphuric acid and Carb. Soda, and threw down a brownish precipitate which appears to be Al. and Iron.
Now examine yours and that together. Does it not resemble the Otaki specimens.
Note on Plumbagenous Coal in America.
(Which will enable you to determine how little, or how much weight belongs to Silurian speculation.)
From Mansfield in Mass. to Newport in Rhode Island, the whole of the coal is altered, so as to appear as Graphite or Plumbago. In Fortsmouth, Rhode Island, at one out-crop, the coal is light, spongy or cellular. It is sold as Plumbago under the name of British Lustre. Asbestos occurs abundantly in the shales near the coal: and that, as well as the shales, are traversed there and in Massachusetts by quartz veins.
Now in this region, the fossils are those of the ordinary coal formation, and thus Dr. McCulloch says, (Vol. II., page 297), coal of secondary origin: containing vegetable remains is converted into plumbago by the influence of trap, as coal is daily in the iron furnaces.
Formerly anthracite in Ireland was confidently spoken of by distinguished Geologists in transition clay slate intermixed with considerable beds of quartz. Now it is universally admitted, that, that entire coal field is of no older date, than the regular bituminous coal fields elsewhere. This was the case also with the Western part of the South Wales coal basin. It was then called “Grauwacke.”
Again, Sir C. Lyell says the rocks which contain the plumbaginous anthracite of Worcester (Mass.) are merely altered rocks, the grits and shales of the coal measures have been thus changed to quartzite, clay slate and mica schist and the anthracite into that state of carbon which is called plumbago or graphite.
See Q. J. S., May, 1845.
Mr. Hall tells us that in one part of South Wales, bituminous coal exists at the top of the same series of beds with anthracite at the bottom,
Coal Fields of Great Britain, sec. ed. page 97.
and without igneous rocks. He thinks internal temperature sufficient alone.
Reading the above in connexion with others from my letters you will see the possibility of a coal field once in existence with you. It is for you to weigh how far the actual evidence goes, if these notes help you I shall be glad.