SECTION AGllOaS LO'SE .MOINTAIN. HI 



Oilliis lonoiisis. M;icliiif;i aiiimlata. 



Ortbis pervetii. Macliirca cariiiata. 



Oitliis testntlinaria. Madurea si).? 



Stwptorhyiicliiis minor. O^Ttolites siiiuatus. 



Goleopiioii iiiinuta. Illii'ims sp. f 



Resting ujjoii the I'dyonip comes the Eiirck;! (juartzitc, hut with less 

 thickness than tlie correspoiuliuf;;- beds at Eureka. Imiiiediately above the 

 quartzite, with but httle development of transition beds, occur the light 

 colored siliceous limestones, measuring' at least 2,000 feet. These beds form 

 the greater part of the western slope of the mountain, iind are so character- 

 istically shown as to make the local name of Lone Jlountain an appropriate 

 one to designate the epoch. In the lower limestones, resting directly upon 

 tile (juartzite, the Trenton fauna appears to be wanting, and it is l)y no 

 means certain that the beds are represented. At all events the Ijluisli gray 

 limestone characteristic of the Trenton at Eureka and White Pine has not 

 been recog-nized. On the other hand, throughout the entire epoch evi- 

 dences of organic remains are exceedingly meager and confined to silicified 

 corals imperfectly preserved. The Niagara coral, Hali/sitrs rnfcnulatKs, whicli 

 usually occurs several ]iun(h-ed feet above, is found liere witliin ')() feet 

 of the quartzite. 



The light colored siliceous limestone pas.ses up gradually into the dis- 

 tinctly bedded Nevada limestone of the Devonian, which forms the summit 

 of the ridge, and as the strata di[) eastward make up the greater part of the 

 eastern slope. It is by no means certain, however, that a dis]»lacement of 

 strata does not extend along the eastern face of the uplifteil mass, the base 

 of tlie ridge not having been examined. 



Mr. C. D. Walcott made the following section across Lone ^Mountain 

 (see Fig. 2): 



Feet. 



1. Dark gray hincstonc, witli brown and variegated layers interhcddcd. 



Typical Devonian I'anna. (Nevada limestone.) 1,500 



2. Siliceous bluish gray limestone breaking up into slialy bands carrying 



abundant fossils of tlie Lower Devonian. (Nevada limestone.) 200 



3. Siliceous limestone, ligbt brown, gray, and butt' in color, with Hah/sUcs 



catenulatiix near tlie l)ase; passing up into beds almost white, with bhie 

 and gray tints, lollowed by alternating daik and light beds. (Lone 

 Mountain limestone.) L', ooil 



