500 THE ORE-DEPOSITS OF BORAH CREEK, 



as the King Conrad Lode. The main lode has now been pros- 

 pected for more than a mile in length, and the ore-values have 

 proved fairly uniform over that distance. Shoots of ore do occur, 

 but these will be considered later. The main drive in the mine- 

 is at the 400-feefc level from the King Conrad shaft, and this is 

 connected right through to the Conrad shaft, about half a mile 

 to the south-west. Several shafts have been sunk on the lode, 

 and these may be seen by reference to text-fig. 2. As the lode 

 outcrops on the summit of the hill, about 400 feet above the 

 King Conrad Mine; and as the deepest level is the 550 feet drive 

 from the bottom of Moore's shaft, the vertical extent of the ore- 

 body has been proved for about 1000 feet. 



The chief minerals present are quartz, galena, sphalerite, 

 arsenopyrite, pju'ite, chalcopyrite, and stannite. The combina- 

 tion of these makes the ore a very refractory one; and the 

 metallurgical problem has, so far, been the stumbling block in 

 the development of the mine. 



The fracture system of the district is worthy of some considera- 

 tion, as it enables the relative age of the ore-body to be deter- 

 mined. Observations of joint-systems show that the following 

 directions of jointing are represented within two miles of the- 

 mine. The bearings are given in degrees, measured clockwise 

 from north, which is taken as the zero-position. 

 25°, 43°, 92°, 103°, and 355°. 



A comparison of these directions with those prevalent in the 

 Elsmore-Tingha tin-bearing area,* some 10 miles to the east, 

 shows that they may all be grouped in the representative systems 

 of that district. The bearing of the King Conrad Lode is 98°, 

 and that of Alwell's lode is 85°. These both correspond to 

 known fracture-systems of the area just mentioned. Tlie main 

 Conrad Lode, however, bears 125°, and does not correspond to 

 any of the important systems of fracture above referred to. This 

 lode, moreover, is thrown by a fault bearing N.15°W., which 

 direction has no representative in the Elsmore-Tingha District. 



* Cotton, loc. cit., p. 752. 



