Geological and other Reports
Wellington, April 13, 1863
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 page 22 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, page 23 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 page 24 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 Raukaa 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 Oroa 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.
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- page 25 nine 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 page 26 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 aunga 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.
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.
|Locality||Height above sea.|
|Brown's Hotel, Upper Hutt||164 Feet.|
|Mungaroa Bridge||248 Feet.|
|Mungaroa Hill||774 Feet.|
|Pakuratahi Bridge||552 Feet.|
|Top of saddle, Rimutaka Road||1636 Feet.|
|mean of three observations|
|Featherstòn||143 feet.page 27|
|Greytown and the same||143 feet.|
|Chalmers (Potsdam)||262 feet.|
|Ray's (Carterton)||236 feet.|
|Donald's, Manaia, (mean of three observations||367 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's||771 feet.|
|Highest point reached on Ruamahunga||1234 feet.|
|Mangawhina stream, (Forty Mile Bush)||947 feet.|
|Camp on Makakahi River||837 feet.|
|Top of hill or terrace beyond Makakahi River||866 feet.|
|Bottom of hill terrace||679 feet.|
|Camp on Mangatainoko||459 feet.|
|Uki Uki pa (on Maungawha)||420 feet.|
|Uki Uki stream at foot of main range||486 feet.|
|Top of main range (say three miles South of Manawatu river)||1402 feet.|
|Bottom of main range (West side)||486 feet.|
Puketotara and Te Awahou show no perceptible height above the sea level, except of course the river bank.
|Wairarapa pa||24 feet.|
|Koaraitea (granite locality)||104 feet.|
|Junction of Otaki and Waiotaueru||304 feet.|
|Camp on Waiotaueru||457 feet.|
|Highest on upper ridges of Tararua||3047 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,
Your Obedient Servant,
James C. Crawford,