Geological and other Reports
Wellington, January 12th, 1863
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 page 7 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- page 8 tarewa. 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,
Your most obedient servant,
James C. Crawford,