ORES OF THE CAMBKIAN. 295 



as those so successfully worked on Ruby Hill, are found throughout a wide 

 vertical range of sedimentary beds. No ore deposits are known below the 

 contact between the Prospect Mountain quartzite and the overlying lime- 

 stones upon Ruby Hill. As will be shown later these limestones on Ruby 

 Hill carry deposits of ore throughout their entire thickness from the quartz- 

 ite to the overlying Secret Canyon shale. 



Along the slopes of Prospect Mountain from Mineral Hill southward 

 to Surprise Peak, the crushed and brecciated limestones have undergone 

 considerable local disturbance and are honeycombed throughout by fissures, 

 seams, and irregular crevices of various width and length. Many of these 

 openings lie parallel with the stratification ; others cut across the beds, occur- 

 ring in the limestone anywhere between the quartzite and shale without any 

 recognized order. Oxidized ore bodies occupy these openings, many of 

 them being connected by narrow channels and seams more or less filled 

 with mineral matter. The William.sburg mine on the west side is a good 

 example of the ore found deposited in characteristic chambers, while on the 

 east side at the extreme southern end of the ridge the Geddes and Bertrand 

 mine appears to be a well defined north and south fissure carrying much 

 rich ore. Among others of the larger bodies of ore may be mentioned those 

 of the Silver Connor and Banner mines, the latter a good example of a fissure 

 which occurs on the summit of the ridge. In but few of these ore bodies, 

 at least on the surface, have any rhyolites been recognized. A marked 

 instance, however, may be seen in the case of the Geddes and Bertrand 

 mine, where a powerful east and west dike cuts the limestone and overlying 

 shale in close proximity to the north and south ore channel. 



Nowhere along the grand exposures of Secret Canyon shales have the 

 ores penetrated to the surface, the pliable, argillaceous clays flexing and 

 folding instead of fissuring, and everywhere serving as an impervious 

 barrier to the ascending currents. Fine examples of dike cutting are 

 shown near the Greddes and Bertrand Mine and again on the summit of the 

 watershed between New York Canyon and Secret Canyon shales, but at 

 the latter locality, so far as known, wholly unaccompanied by important 

 mineral matter. 



The beds of the Hamburg limestone are similar in their structural 



