✨ Geological Expedition Report
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feet wide, which was not covered when the tide rose. On this ledge we managed to establish ourselves, removing the most angular of the blocks of rock with levers, in order to find room to lie down.
We had deep water on the one side and a more than vertical precipice on the other, so that there was not much room for exercise, and all our firewood and water had to be fetched with the boat.
We spent three days and nights imprisoned on the rock, during which the storm continued with unabated violence, with thunder and lightning, and a heavy snow storm on the mountains. At first the Maoris caught plenty of fish close to the rock, but they soon began to get scarce, so that on the morning of the 6th, although it was still wet, we pushed on to the head of the Sound.
I regretted that the mountains were so covered with clouds, as, judging from the partial peep obtained, the scenery must be very fine. The mountains are very lofty, and rise steeply from the limit of the woods, which at this season is the same as the snow line, but there are lower and broken ridges that skirt the valley, which relieve the scenery of the bald appearance usual in these Sounds.
Several streams enter the head of the Sound, and on the principal one there is a splendid waterfall, 80 or 100 feet in height, over which an immense body of water was pouring in consequence of the floods. Above this fall I understand there is a large lake, but the bad weather prevented my visiting it. There are shingle flats at the head of the Sound, but though heavily timbered they are barely elevated above flood mark. The Maoris could not snare woodhens on account of the stormy weather, and my gun was of little service from the same cause — although there were plenty of ducks of various kinds.
As there was no dry place to camp, we returned again to our rocky ledge, where we passed a fourth night. On the way down, the Maoris caught eleven of the large fish called Harbuka, or Groper, of about 30 lbs each. These fish are generally plentiful near the shores at the head of the different Sounds.
By next day the storm had abated, so that we started early on our return down the Sound, and reached Cuttle Cove in the afternoon.
Next day, I consented, though with some reluctance, to the Maoris again leaving us, as Murphy wished to camp on Chalky Island, both on account of its being a good fishing and sealing place; and also because it was more conveniently situated for starting with the first Southerly breeze for Dusky Bay. I now begin to perceive that it will be a loss of time to try to examine the coast working northwards, as the winds from the S. and E. are very rare — the prevailing winds being from west to north-west.
As we had at this time low tides during the day, I was able to make a better examination of the carbonaceous strata in Coal Island. The only seam of coal I found is from 4 to 9 inches in thickness, and dips at an angle of 15° to the east. It, however, again crops out, with an opposite dip, a few hundred yards nearer the junction of the series with the underlying slates. It is only exposed at very low tides; but, once seen, it was easily traced back to the brow of the hill, which rises steeply from the shore at this place; but is so obscured by fallen debris and dense scrub that a further search in that direction would be an expensive and tedious operation.
The following is the section of the strata, which lies at right angles to the shore and forms rocky ledges jutting into the sea, and covered with kelp:
Massive coarse-grained sandstone, composed of granitic sand, and resting on the edges of the slates 100 ft.
Argillaceous sandstone in the flags with obvious plant impressions and straits of coal 250 ft.
Coarse grit passing into conglomerate, the pebbles being principally rounded fragments of slate 30 ft.
Laminated sandstone 10 ft.
Coal 4 to 9 in.
Pipe clay 6 inches
Blue clay shale 4 ft.
Sandstone 6 ft.
Blue clay shale 6 ft.
Grit 20 ft.
These strata are the same as those displayed on the south side of the island, where they have the same trend and general order of distribution, so that it is probable that they pass right through and form the mass of highland in the interior of the island. Immediately to the west of where the coal was found, the strata are suddenly thrown up at an angle of 35 deg., and the lower flaggy sandstones attain a much greater development than that given above, and from the whole thickness of the cliffs exposed along the sea-coast, so that the above seam of coal, if it occurs at all, must be at an elevation of 200 to 300 feet above the level of the sea, and on the tops of thickly wooded table land. It is, however, extremely improbable that such a seam will prove persistent over a large area; but, while it may suddenly thin out altogether, it is just as liable to expand into a thick and valuable seam of fuel; such is the irregularity of deposits like this, which have been formed in a very limited basin, subject to sudden changes in the nature of the sediment with which it was gradually filled up. We mined about a ton of the coal, and taken from the outcrop, where exposed alternately to the sea and the atmosphere, we found it of excellent quality — quite equal to the Sydney coal which we had on board, to which it bears a great resemblance
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Geological Expedition to the West Coast of Otago
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🌾 Primary Industries & Resources19 October 1863
Geological exploration, West Coast, Otago, Report, Expedition, Edwardson Sound, Kakapo Mountains, Rock formations, Glaciers
Otago Provincial Gazette 1863, No 274