The Southern Goldfields

Hawke's Bay Tribune, Volume XXII, Issue 272, 1 November 1932, Page 5

The Southern Goldfields

Trip up the Shotover

Old Workings and Prospecting

The Mining Revival

(Contributed by

Mr. G. F. Clapcott,

member N.Z. Society

Civil Engineers.)

The object of the visit was to inspect and report on a gold-mining and hydroelectric scheme located in the upper reaches of the Shotover Biver, some 30 odd miles beyond Queenstown and 45 miles in a direct line from Milford Sound. The run down Lake Wakatipn from Kingston was full of interest. The rugged grandeur of the mountains viewed under late winter conditions was particularly fine. The afternoon being fine the rays of the setting sun, reflected on the snow-clad mountaintops, were strikingly beautiful. The following morning we, a party of four, left Queenstown by car for Skippers. As our car was the first to make the trip since a heavy fall of snow some days previously, the driver had doubts about getting through. Although the road was snow-covered most of the way, it was safe for travelling at a very slow speed, the most dangerous portions being where small'streams crossed the road. These being frozen over, including a considerable section of the road adjoining, necessitated careful driving, as, apart from the slippery surface, the road is very narrow. PRECIPITOUS COUNTRY. Along the whole route the road follows up the Shotover gorge which is very precipitous, and practically devoid of vegetation other than stunted tussock. The remains of miners’ huts, pipe lines, and suchlike are to be seen scattered about on the hill slopes. This gorge was a scene of great mining activity in the early days. To-day mining operations are only being carried out in limited areas of the river-bed that can be worked, also on the adjoining terraces where water is obtainable at sufficiently high pressure to permit of hydraulic sluicing. One pictured the strenuous work that must have been put in in the man-handling of water pipes up and along the mountain and gorge face to permit of I tapping a mountain stream at sufficient elevation to provide the pressure and volume of water required to work the alluvial terraces. A RICH CLAIM. Looking down into the river-bed we observed a party of miners engaged in putting down, by hand, a bore for the purpose of testing the value of the river sands and gravel. The general experience is, and has been, that the rock bottom of the river-bed contains gold in quantity. But as this rock bottom has an over burden of some 16 feet deep of gravel, with the river flowing on top of same in a gorge, one can realise the great difficulties there are in getting down to the gold. To give an illustration of the richness or a claim visited, the miniTs had (after diverting the river sufficiently to allow of' sinking down through the shingle) obtained £1,200 worth of gold in 38 hours. But immediately the river rose 12 inches their claim became flooded, which necessitated a long wait for drier conditions before a fresh start could be made. METHOD OF PROSPECTING. The method generally adopted is first to make a low wing dam of rock in the river-bed to deflect the river to one or other side of the gorge. This is only possible on limited reaches of the river where the bed is fairly wide. Following on this, a large hole, or “paddock” (the mining term) is sunk in the shingle covering the portion of the bed now temporarily freed ot water. The sinking is carried out with a hydraulic elevator. Water at a high pressure is delivered into the lower end of a large pipe resting on the bottom of the excavation, and the water volume and velocity lifts the shingle up the pipe to the surface; there the spoil is discharged into box fluming, covered with matting on the bottom to catch the gold as it is freed from the wash dirt. Under favourable conditions the whote operation is fairly simple, providing that there is a large supply of water at high pressure, and that the river maintains a dead low level. Failing these conditions a great deal of real hard Work is resultless. This mine is difficult of access. To get down to the river-bed one has to traverse narrow mountain tracks, descend a 30ft. cliff by rope, and cross the river on a small seat suspended from a travelling pulley on a wire rope. IN THE RIVER GORGE. Reverting to the trip; at the end of the car road we transferred our swags and provisions on to a pack-horse. From here we continued our journey on foot along a good track for a distance of six miles to the hut in which we proposed to camp for the night. Some two miles from the hut the river gorge opened out into a fairly wide shingle bed, and tow terrace formation. Quite a relief after the precipitous gorge country we had passed through. Immediately beyond the terraces, and as far as the eye could see, snow-clad mountains extended in every direction. The extreme silence that prevailed struck one at first as being almost uncanny, but at the same time one was impressed with the grandeur of the surroundings. THE RIGHT-HAND BRANCH. Our first night in the hut was not too comfortable on account of the cold, but after a good breakfast we all felt quite fit for exploring the four miles of river-bed that the company proposed dewatering for the purpose of carrying out mining operations in the shingle beds and down to the rock bottom. The stream is the right-hand branch of the Shotover, and like all the watercourses in the district is confined within a deep, narrow gorge. As the day was beautifully fine the four-mile walk along the terraces above the stream was interesting travelling. We inspected, as we passed along, a small lake, which was completely frozen over. In the summer time this is a haunt of paradise duck. Along the terraces we came across traces of old mining operations. Water for sluicing the alluvial gravels had

evidently been brought by open waterrace from a small creek some miles up the gorge. As no work had been carried out here since the early ’seventies little now remains of the race and small storage reservoirs. .PROPOSED DIVERSION SCHEME. On reaching the upper portion of the proposed claim an inspection was made of the suggested site for a tunnel through a narrow ridge, the object of the tunnel being to divert the Shotover branch into a deep gorge adjacent. I descended to the bottom of this gorge, which is 260 feit below the ridge. For some distance up from the bed it was more or less ice and frozen snow—as fine a freezing chamber as one could desire. Needless to say I did not remain there very long. Once more on top of the ridge we had lunch. Here again one could not help being impressed by the great silence and the snow-clad ranges rising precipitously from the various gorges. With the exception of one hawk, there was not a sign of any bird or animal life. Lunch over we inspected the bed of the stream that is to be diverted. This is some 140 feet higher than the adjoining gorge. The rock formation in both gorges is schist (a kind of slate formation common throughout this portion of the Otago district).. We followed down this gorge for some distance until blocked by the cliffs and the frozen condition of the stream. 1 had my first experience of wading in frozen water after breaking through a thin crust of ice. I came to the conclusion that one had to be in walking on ice, and well seasoned to enjoy wading in the water.. Returning to the hut we soon had a fire going and the billy boiling. That night we slept more comfortably. One of the party took a large lump of heated rock to bed as a foot warmer. LOWER REACHES EXPLORED. Next morning we explored the lower reaches of the stream, and also the open beaches. Here, in places, traces of very old mine workings cpuld be seen, mostly on the terrace formation. Here we judged that operations must have been hampered due to tack of sufficient water. The stream bed, Owing to the narrow nature of the gorge and large volume of water running in it, could never have been worked, except in one or two open patches. Here the usual methods had evidently been adopted, i.e., wing damming and sinking as deep as possible down through the shingle and passing the wash dirt through goldsaving sluice boxes. After lunch we caught our pack-horse and loaded on the swags, and started on our return journey, arriving back in Queenstown before dark. | CLAIM NEAR GORE. Out of Gore I visited a sluicing claim situated in open country only three miles from the town. Here water is pumped from a creek up to the low hills composed of alluvial gravel. The water pressure at the nozzle is 601bs. per square inch. With this pressure the hill face is sluiced down, and the spoil after passing down a long length of gold-saving boxes is deposited in a guiley. The gold which is fine, is contained principally in the black sand mixed with the wash dirt. The Shotover River gold is very coarse. The value content of both grades is high. The Gore mine is the most conveniently situated gold-mine I have seen. What makes this a workable proposition is the using of electrio current from the Power Board, permitting of water, which is in abundance at a low level, being pumped by a compact pumping outfit up, and at the required pressure, to the hill ground being sluiced. ELECTRICAL AID TO SLUICING. Electric power where it is available or can be developed cheaply is, in my opinion, going to permit of large areas of gold-bearing country being mined at a profit ; country that otherwise could never be worked. Water in large volume is essential for sluicing and this can only be obtained from permanent streams, which invariably are situated at too low a level to be of service. With cheap electric power, and a portable electrically driven pump this water can be delivered to any height, at the pressure that is desired. Wherever one went gold prospecting and development works in connection with mining appeared to be looked upon as one of the most important industries at the present time; and no doubt it is, if carried out on sound lines, and “wildcat” schemes are avoided.