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a search in the locality and, within a stonethrow of the old battery, found a large block of quartz which carried gold. The writer visited this find and took two samples from it, one of which yielded on assay gold at the rate of over 1 oz. per ton, the other being barren. Samples were also taken at the same time from several other reefs outcropping a short distance higher up the range, but none of them when assayed revealed any gold content. Two short adits were driven a little later under the block of stone found by Rasmussen, with the result that it was found to be merely a boulder contained in a large slip that had come down from a higher level.
In view of the specimen gold got in such quantity in Moonlight Creek and its upper tributaties, it would appear that somewhere in the area drained by the creek rich gold-bearing reef must once have existed, and probably still exists and will some day reward the efforts of the prospector; but the country is rugged, heavily timbered, and very difficult to get about in, and few men are now willing to face the extreme hardship the investigation of such places entails.
Poerua Reefs.—The only other area in Grey County calling for particular mention as having revealed auriferous quartz is one lying on the extreme east of the county, in Block I, Otira Survey District, about two miles north of Jackson’s Station on the Greymouth-Christchurch Railway. About 1910 the Poerua Gold-mining Company was formed to work some reefs that had been discovered there, near the head of Peter’s and Homestead Creeks. Quite a number of outcrops were located, amongst them those known as the South lode, Peter’s lode, Blind Gully lode, Homestead lode, and Farmer’s lode, and a certain amount of prospecting was done on each of them. The lodes occurred in mica-schist country, and had on the surface a nearly east-and-west strike, with an apparent underlie to the south at an angle of about 30°.
The most extensive exploration was done on Peter’s lode, on which two adits, 80 ft. apart measured on the dip of the lode, but only 40 ft. vertically, were driven, the lower of which (No. 2) followed the course of the lode for 700ft. A winze was also put down from No. 2 adit to a depth of 200 ft. on the dip of the lode, from which, at 90 ft. down, another level was started. The result of all this work was to show that, while small pockets of reef carrying fair values existed, the value of the reef as a whole was extremely low. Acting on ill-considered advice, however, the company erected a ten-stamp battery, equipped with Fraser pans, agitation tanks, cyanide plant, &c., at considerable expense, and crushed 600 tons of lode-material from between No. 1 and No. 2 adits for the poor yield of 23 oz. 11 dwt. 5 gr. gold, valued at £88 1s. 6d. This yield was only equal to a trifle over 9 gr. gold per ton.
P. G. Morgan, Director of Geological Survey, visited the mine in 1912, when the two adits had been driven and the winze from No. 2 adit sunk 110 ft., and his report (Mines Reps., 1912, C.–2, p. 128) was to the effect that up to that time the result of the mining operations was to show the existence of a block or shoot of ore with a possible average width or thickness of 2ft., 100 ft. to 120 ft. in length at the most, and apparently pitching to the westward on its downward course, the average value of which probably did not exceed £1 per short ton of 2,000 lb.
The winze was, as previously mentioned, subsequently sunk to 200 ft. on the dip of the lode, but in the further sinking no more satisfactory values were revealed, and the information at hand indicates that the mineral-bearing part of the formation had narrowed to a few inches in width.
