522 E. BLACKWELDER GEOLOGY OF WASATCH MOUNTAINS, UTAH 



several yards thick and is composed of rounded pebbles^ largely of 

 quartzite, with occasional pieces of gneiss and vein quartz. The contact 

 was found first in the bottom of the canyon, was traced 500 feet up the 

 south slope, and was found again on the front of the range two or three 

 miles north of the mouth of the canyon. Between the two sets of beds 

 there is but little angular discordance, but as seen from the south slope' 

 of Big Cottonwood Canyon the contact gradually truncates the individual 



Figure 2. — Diagram shoioing the Relations of the Camhrian and Algonkian Quartzites 



The locaUty is about 1% miles below the Maxfield Mine in Big Cottonwood Canyon. 

 The diagram is made from a poor photograph 



layers of the underlying quartzite (see figure 2). The truncation of the 

 beds may be inferred also from the relations of the conglomerate to the 

 underlying rocks at different points. Thus, in the bottom of the canyon 

 it lies on white quartzite; several hundred feet up the south slope it lies 

 upon hard gray shale, and still higher on quartzite again. In the locality 

 on the front of the range the conglomerate rests upon purple and gray 

 shales at the point examined, but evidently passes over upon quartzite 

 higher on the spur. 



