Page:Downey•Quartz·Reefs·West·Coast•1928.pdf/13

The one reef traverses all the claims on a north-north-westerly strike, and with an underlie varying from 30° to 75°, and is traceable on the surface for about 90 chains. A very considerable amount of development has been done on it, mainly within the boundaries of the Empire City and Golden Bar sections (see Fig. 1). Four adits were driven in the Empire City Claim, and a fifth was started. In the surface adit, No. 0, there was solid reef for 500 ft., and in Nos. 1 and 2 for 1,100 ft. and 1,350 ft. respectively. No. 3 adit was, however, in crushed country carrying streaks and veinlets of calcite and quartz. An intermediate level was driven from No. 3 rise on No. 3 level, and only 15 ft. above the latter, and this was extended for 850 ft., the last 350 ft. of which was in solid stone, which was afterwards stoped to surface. At a point above 650 ft. along this intermediate level a fault or break was intersected which cut the reef off, but on driving a few feet through it the reef was picked up again on the Golden Bar side, which was, subsequently, also stoped out to surface. This was the only level on the Empire City side that penetrated the break. On the Golden Bar side two adits were put in, No. 1 being 40 ft. below the Empire City intermediate level, and No. 2 120 ft. lower. Both these adits were driven on solid stone up to 8 ft. to 10 ft. wide. A good deal of stoping was done along each, but the ore on the whole was of low grade. In 1925, No. 1 Golden Bar adit was driven to the break previously referred to, when further advance was stopped. In 1926, however, under the management of Mr. Harrison, the break was penetrated at this point, with the result that the reef was picked up beyond it in a few feet of driving. It was about 8 ft. wide where struck, but opened out quickly to nearly 20 ft., and was apparently richer in gold than the stone found in any other part of the mine, for it was from here that all of the decidedly improved quality quartz evidently came that was treated in 1926.

Henderson^[1] describes the country in which the reef occurs as consisting of gently dipping schists evidently altered from massive greywacke containing thin bands of finer material, and the reef itself as a fissure-lode, formed by the replacement of crushed rock in a fracture-zone by quartz, calcite, scheelite, pyrite, and gold derived from the general mass of the schist, the vein material having been brought to its present position by surface waters. On the surface the reef is massive, but with depth it shows a tendency to split up into an aggregate of small veinlets, indicating partial replacement of the crushed and sheeted country. Thus, while Nos. 1 and 2 levels of the Empire City Claim were driven in solid ore for 1,100 ft. and 1,350 ft. respectively, No. 3 was driven 750 ft. in a formation consisting merely of stringers and veinlets of quartz, while in the Federation lease on the other end of the line a tunnel driven under solid quartz only cut a similar zone of silicified country. Towards the centre line of the property the solid reef may, however, carry to considerably greater depth, and has indeed been proved to live down to No. 2 adit of the Golden Bar, 160 ft. lower than No. 2 Empire City, and there is in the former a run of fully 1,000 ft. of compact reef.

In view of the developments at the mine under Mr. Harrison's management, and of the fact that in the intermediate above No. 3 level in the Empire City section of the mine a run of some hundreds of feet of solid reef occurred north of the break, it seemed reasonable to expect that a similar run of good stone would be got down to, and below, No. 2 adit of the Golden Bar. Some further prospecting carried out, in the nature of driving the latter adit, and rising from it to No. 1 adit, served to show, however, that