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University of California Publications in Geology [Vol. 13 



granite. Although no fossils were found in this quartzite it is probably 

 Cambrian in age. About 10 feet above the base of the quartzite there 

 is a 10-foot bed of conglomerate, composed of quartz pebbles in a 

 quartzite matrix. The lowest 2 or 3 feet of quartzite are usually 

 cross-bedded and often contain feldspar fragments, but the greater 

 part of the stratum is made up of well sorted and rounded quartz 

 grains firmly cemented together. An arenaceous shale having an 

 average thickness of 22 feet rests conformably on the surface of 

 the quartzite. It contains numerous beds of quartzite from 1 to 3 

 inches thick and is highly fossiliferous. A bed of very hard, dark 

 blue to black, nodular limestone or marble lies conformably above the 

 shale and is quarried for marble in several places. Although no 

 fossils were found in this limestone it is considered to be the upper 

 limit of the Lower Cambrian. 



Middle Cambrian. — The Middle Cambrian, as determined by a few 

 fossils, consists of a massive arenaceous shale resting conformably 

 on the nodular blue limestone. The shale is light gray to brown or 

 black, and contains numerous beds of quartzite and calcareous 

 sandstone. Although a careful search was made for fossils in this 

 shale the writer was unable to find any ; but Mr. Cavins, at the request 

 of the writer, revisited the region and found a few specimens of the 

 trilobitc Bathyuriscus about 12 feet from the top of the shale bed. 



Carboniferous. — The Carboniferous is represented by a thick bed 

 of massive limestone or marble which rests apparently conformably 

 on the Middle Cambrian shale. A few fragments of fossils consisting 

 of very poorly preserved, rounded, crinoid stems and faint impressions 

 of coral were found on the upper surface of the limestone. Mr. Darton 5 

 reports numerous fossils which he found in the upper part of this 

 limestone that definitely place it in the Carboniferous. Owing to the 

 massive character of the entire bed of limestone, notwithstanding 

 the lack of fossils in the lower portion, it is all included in the 

 Carboniferous. 



5 Personal communication. 



