CARBONIFEEOUS COAL. i)5 



At the extreiiic northern end ot'the district, on the west slope of I )iamon(l 

 Peak and north of Garden Creek, in a very siniihir limestone, the beds 

 yielded as follows: 



Fusiliua cyliii<lric-a. I'roductiis pratteniaiius. 



Chaetetes, sp. ? Productus se.mireticulatus. 



Zaphrentis (fragments). Spiriferiua cristata. 



Ptilodic'tya (Stenopeia) carboiiaria, ? Athyris siibtilita. 



Ptilodictya (Sti'iiopera) st'irala, ? Ketzia niormoi}!. 



A complete list of fossils from the somewhat restricted fauna of tlie 

 Ui)per Coal-measures will be found at the end of this volume. 



Carboniferous Coal. — In the tirst rani)-e to the east of the Kureka District, 

 Carboniferous formations extend for miles alonji" the edg-e of the valley 

 which in a study of Paleozoic rocks present some ]ioints of more 

 than ordinary interest. It is the only range in the Great Basin where coal 

 of Cai'boniferous age has been discovered in anything like a well defined 

 seam of sufficient thickness to encourage exploration, althougli ])eds carr\-- 

 ing small amounts of carbonaceous matter are known in one or two other 

 localities in central Nevada. Two outcrops of this coal are known and 

 considerable ex])loration has been undertaken in order to determine the value 

 of the coal seams: one is situated on a low flat hill known as Pancake Ridge, 

 and the other on Bald Moimtain, which stands out prominentlvat the southern 

 end of the Humltoldt Range. Pancake lies about eight miles to the west- 

 ward of the Eureka District in a mass of low ridges connecting the 

 Humljoldt Kange with the White Pine Mountains. Rising above tlie plain 

 occiu's a l)odv of rhyolite, beyond wliich is a low ridge of coarse conglouK- 

 erate followed by a second ridge somewhat lugher than the first with an 

 intervening valle}- or shallow depression. Along the western base of this 

 second ridge an exposure of dral) cla\- shales crops out onK- a few feet in 

 tliickness, striking approximatelv north and south with a low dip to the 

 east rarely exceeding 10°. This clay carries a seam of lignite varving 

 from 10 to 18 inches in width which niav be readih' traced for nearly !;")() 

 feet along the line of outcrop. Both above and Ix-low this coal .seam are 

 alternating layers of bituminous .shale and ])urer clay shale conforniablv 

 resting upon a bed of coarse conglomerate. Above the clay shules c<,)mes 



