NOTES ON MINING PROSPECTS OF VARIOUS PARTS OF STEWART'S ISLAND

Otago Witness, Issue 1583, 25 March 1882, Page 22

NOTES ON MINING PROSPECTS OF VARIOUS PARTS OF STEWART'S ISLAND

GOLD DISCOVERY AT PORT PEGASUS.

This discovery is due to the enterprise of Mr L. Longuet, of Invercargill, who for some j time past kept miners engaged in prospecting different ; parts of the country surrounding the Eort, and the prospects disclosed justify the elief that he will be rewarded by the gold produce of. the 50/ acres of purchased ground on which' 'he^recently started sluicing operations. The 'auriferous ground intended to be worked commences close to the head of one of the main branches of the port, at a point where a rather strong creek running in from, the north forms a fine waterfall of some 20 feet in height, over massive beds of hard mica schist; For a distance north of about a quarter-mile above the waterfall the denselywooded creek valley is. narrow, and rises rather steeply, but there are at several points — generally where small gullies join in from the sides — small triangular flats, and it is in one of these flats, several chains above tho waterfall, where working .is at present carried on. The alluvium consists here of a deposit of from 1 to 2ft.vin thickness of coarse granite detritus intermixed .with larger and smaller pebbles, and' boulders of mostly quartz and granitic rocks, and above this 6 to Bft. of sandy loam and humus. The bottom is composed of soft mica schist, and is full of little furrows and hollows. » The gravel is the gold - bearing stratum, and a tin-dishful of it washed in my presence gave a fair prospect of fine waterworn gold more shotty than scaly in character. Mr Longuet showed me about one ounce of the same kind of gold, obtained, he said, from scarcely over two square yards in extent of tho ground worked. During washing off the heavy sand is found to be full of small crystals and fragments of garnet. Owing to the expensive mode of working adopted— entailing, as it does, the cost for the stripping of the over-burden by pick and shovel, and the carriage of the washing stuff some distance to the sluice at the creek, the amount of gold saved (leaving the chance of striking other patches Qut of consideration) cannot, in my opinion, 10/iye much profit. But if Uio fine natural facilities of the ground were made use of for systematic groxaid or hydraulic sluicing, there is, 1 think, every probability of a. handsomo surplus being realised

over working expenses. Sluicing should in fact be started, and progress up the valley from the head of the waterfall, to which pomt, in the case of hydraulic sluicing being adopted, water could be conveyed by flume with a pressure of perhaps 80ft or more, without o-oing higher up the creek for the starting of the flume than about half a mile. The construction of a race instead of a flume might first suggest itself ; but considering the nature of the ground this course would, I think, be much more expensive, irrespective of the fact that the race would be valueless after the work-ing-out of the narrow valley, while the flume .could be made use of in the working of other auriferous ground, presently to be noticed. About a quarter of a mile above the waterfall the ' valley suddenly expands into what may be called a wide open flat, but which, in reality, consists of a succession of low and broad rises, divided by small water-channels or swampy ground, and bounded on either side (east and west) by gradually rising ranges which, several miles northward, join the main range of the Island. 1 The Strong Creek divides into a number of small branches at but a short distance up , this broad valley. Across one of the low rises, distant about half a mile from the waterfall, a trench, above a chain in length, and 2ft to 3ft deep and broad, has been cut in soft decomposed granite, traversed by a number of •well-defined quartz-veins — the largest . several inches in thickness. A quantity of the stuff thrown out of the trench gave, according to Mr Longuet, on washing, fine scaly gold, but 'not in sufficient quantity to pay working expenses, regular sluicing being impossible at the place on account of the scarcity of water. The gold is, I think, only contained in the sur face, which here consists of a layer but a few inches in thickness, •of granite detritus, hardly distinguishable from the decomposed granite bottom on which it rests. This surface detritus is, like the drift of the narrow creek valley, very rich, in small crystals and fragments of garnet, and extends most likely over all the low rises in the valley. A third place where the existence, of gold has been proved is situated about a-half mile north from the previous one, up the broad valley — [i.e., about a mile from the waterfall. AlI though the results of the washings were here I also not of a paying character, still I may at once state that I consider the place well worth a more extensive and appropriate trial. A deep trench, dut for sluicing purposes up the slope of one of the low decomposed granite rises, shows that, close, to the extensive flat top of the rise, the granite dips at an angle of about 50deg. northward into the hill, and that the ground beyond consists of a cemented, thoroughly waterworn, quartz boulder drift, much resembling some of the hill drifts of the Bendigo, Forest Creek, and other Victorian goldfields. The surface boundary of this drift .can, on account of dense vegetation, not be seen,' nor has its depth been ascertained, for the workings at the head of i the trench extend only to a few feet in depth over a. very small 'area. Still, whether the drift fills a basin-like hollow, or— what seems to me more probable — occupies an old watercourse, !and as such represents a real old lead, all analagous cases point to the probability that, as the existence of gold in the surface portion has been proved, the bottom por- , tion may be payably, if not richly, auriferous. A | shaft sunk into the drift some distance north from the edge of the granite would soon test this question, and should , the result be favourable, and more especially in case" the 'existence of a real ' lead be proved, the field for remunerative working would be of considerable exjent-^-might, in fact, reach up to 1 the foot of the main range, distant several miles. Regarding the ' quartz reef or reefs' from wHich the , alluvial gold, in the valley has dojibtless' been ' derived, they must, in my opinion, be searched for in the higher ranges at*the<nead of the .valley — a prospecting work by! no means easy of accomplishment; con- 1 sidering' the densely-wooded character of the country. 1 . GOLD DISCOVERY AT PORT WILLIAM.

This discovery was made some years ago by. Mr Cross, a resident of the Port, who. was unfortunately absent at the time of our visit. THere are two places at which working has been carried on with, I understand, tolerable success ; both being situated on the low range onjthe right hand side of, and not far from the entrance of the port— one on the slope within thp harbour, the other right across the range frefm this place on the seaward Blope. At both places the shore sand is nearly black from magnetic andtitaniferous irons and abundantly intermixed. Fair yields of gold were first obtained by Mr Cross from the washing of this sand at the place within the Port, and the gold was also placed in the rock detritus some distance up the slope of the range. The presence of quarts specimens in the drift led to the i driving of an adit by which at a distance of about 60ft a quartz reef was disclosed, which, on being followed some' 2oft in strike, proved to vary in thickness from lft to nearly 3ft. A sample of the quartz tried in Melbourne is said to have produced at the rate of over one ounce of gold per ton. Assuming these reports about the thickness and auriferous quality of the reef to be correct, the latter certainly deserved to have been further opened. As the case stands the tunnel is inaccessible through partial collapse, and the place seems altogether neglected. At the second place of working, across the range, a good patch of fine gold is said to have been found in the black sand near the seashore, and, judging from the rather extensive excavations and .waste heaps up a slight de- j pression in the range, working of the alluvial drift there accumulated in what was doubtless originally a deep rift, must also have proved payable. Regarding the geological character of, the rocks at the two working places, we see from the entrance of the Port up to and beyond the first place massive outcrops of course and fine-grained varieties of diorite, in places traversed by numerous small quartzveins, while at the other place, on the seaward slope of the range, rathor micaceous granite is exposed in one of the excavations. This rock cannot, however, extend far up the range, judging from the abundance of boulders of diorite in the waste-heaps, which evidently prove that this latter rock extends from inside the Port across the top of tho range, and most likely a > good < way down tho seaward slope. In consideration of the fact that at Wood's Point, Alexandra, and other mining districts in Victoria, as well as in certain of the goldfields in New South Wales and Queensland, quartz reefs and leaders traversing diorite-dykes have generally been found auriferous, some, indeed, veryrichly sort is certainly not going to far to say that tho geological character of the locality under notice is favourable for a more abundant occurrence of gold than hitherto disclosed, and that therefore, especially the portion of the Port range composed of diorite rocks, deserves more extensive prospecting than it has received up to the present.

COPJMSK. DISCOVERY AT PATTERSON'S INLET.

About this I regret not to be able to report favourably, nor to hold out any hopes of improving prospects heing obtained on opening' up of the place. Jt consists of nothing elso but a fgw small patebca of groon colour, on

rather decomposed micaceous granite. These patches are due to a very thin coating of green carbonate of copper, and as, on close examination, the granite is found to be abundantly impregnated with small particles of common iron pyrites— an ore that nearly always contains small traces of copper, the origin of the copper stains is easily accounted for by the decomposition of this pyrites. From the fact that only a short distance from this place argillaceous mica schist, also rich in. iron' pyrites, crops out along the shore, the boundaries between this rock and the granite must lie very near, and as we have records that along such division lines the occurrence of ore deposits of copper and other metals is no rarity, an exploration of the respective boundaries would be recommendable. So also would be the testing of the alluvial drift for gold of a densely-wooded gully situated between the granite outcrop, showing the copper stains and the mica schist. _ In conclusion, I may state that from aU I have seen and heard of the rocks occurring m the Island, I consider the latter a promising field for the enterprising prospector, not only with regard to the finding of gold, but also 6i copper and tin ore, for the occurrence ot which latter the granitic tracts seem to me especially favourable.

George H. T. Ulrich.

Dunedin, March 14th.