196 GEOLOGY OF THE EUKEKA DISTRICT. 



fauua. The specimens, although poorly preserved, allowed of the following 

 determinations: 



Stromatopora sp. t Modiomorpha sp. 



Spirifera sp. ! Holopea sp. ? 



Atrypa reticularis. Euomphalus (P) laxus. 

 Pentamerus lotus. 



Pahranagat Range. On the west side of the valley the Pahrauagat Range 

 forms a long, continuous ridge, for the most part made up of sedimentary 

 strata faulted and broken into massive blocks by outbursts of acidic lavas. 

 Quartz Peak, the culminating point, affords a fine exposure of Silurian 

 strata, with much the same series of beds as seen in the central part of the 

 State, with this exception that neither the Upper Pogonip at the base nor the 

 Niagara at the summit are represented in their full development. Upon the 

 south side of the peak, extending from the base to the summit, there is an 

 unbroken exposure of strata 2,000 feet in thickness, striking N. 30 E., 

 with an average dip of 20 N. The summit of the peak is formed of the 

 Niagara limestone. The section, with the accompanying fossils, is, accord- 

 ing to Mr. Walcott, as follows: 



LONE MOUNTAIN NIAGARA. 



Feet. 



1. Massive bedded gray siliceous limestone, with occasional layers of sand- 



stone and chert 535 



LONE MOUNTAIN TEENTON. 



2. Massive bedded dark siliceous limestone, with a stratum 30 feet thick, 



almost made up of a species of Pentamerus like P. galeatus. These 



occur not far above No. 3 335 



3. Bluish black and bluish gray thin bedded limestone, with numerous fossils . 30 



Zaphrentis, sp. ?, Bryozoa, 3 sp., Streptorhynchus filitexta, Orthis tes- 

 tudinaria. 



4. Massive bedded dark iron -gray siliceous limestone : 150 



EUREKA. 



5. Hard, vitreous white quartzite, becoming tinged with a reddish color toward 



the base 400 



