MOUNT BISCHOFF. 



367 



clean ore, in places over two feet wide, was discovered in the 

 prospecting drive fully 350 feet below the surface. This, up 

 to the jjresent, has not been the case in the North Valley- 

 Mine, perha}>s on account of its quickly-increasing greater 

 depth below the surface, as every foot in advance into the hill 

 increases this depth rapidly. Still, since the Mount BischofF 

 Company has acquired this property some very good pyritous 

 ore has been taken out. Both the JNorth Valley and the 

 West BischofF lodes traverse, in slate, with clean walls, when 

 productive, but in non-productive parts the lodestone is inter- 

 mixed with the hanging- wall or foot- wall, or both. 



From this description it will be seen that so far we have, 

 in the original BischofF workings, not been successful with 

 deep mining, which was rather neglected on account of the 

 large deposit so near the surface. The deepest work is the 

 main tunnel, which passes through the hill about 260 feet 

 below the crown of the Brown Face, crossing in its course the 

 different porphyry dykes, which carry tin ore in small quan- 

 tities, associated with tourmaline, and, in places, iron pyrites. 



The western cross-cut, bearing for the summit of the 

 Mount, is all in altered (silicious) slate and sandstone, and 

 crosses several thin quartz veins, of which two contain 

 native copper and the others a little tin ore ; on account of 

 the hardness of the ground they are of no particular value. 

 We passed through the porphyry dyke of the summit of the 

 Mount several hundred feet further west than its outcrop, 

 which proves either that it has a strong westerly underlay or 

 that there did exist a disturbance in the ground. This dyke 

 was found very hard and barren. 



There is another question which may be of some interest 

 and deserves mentioning, and that is the probability of deep 

 leads existing in the neighbourhood under the basalt, as is 

 the case in Victoria and other places with gold, and in New 

 South Wales and Queensland with tin ore. In three direc- 

 tions from the Mount there is evidence that stanniferous 

 drifts exist below the Mount BischofF workings — northward 

 in the North Valley, southward in the old Don Company's 

 property, and south-westward Tin Creek. In Tin Creek tin 

 ore was first found by the discoverer of the BischofF mine, 

 and ultimately led to the discovery on the Mount itself. 

 Nothing of value, however, could be afterwards found in Tin 

 Creek, as the ore was confined to a thin layer of wash occur- 

 ring next to the bottom, and the ground taken up was soon 

 abandoned. 



