138 GEOLOGY OF THE EUREKA DISTRICT. 



limestones cross Denio Canyon and continue northward to l^nrlingame 

 Canyon, invariably dipping slightly to the northeast. 



About 150 feet above the bottom of Browns Canyon, in beds near the 

 base of the Nevada limestone, a small number of fossils were ^n'ocured, 

 most of them like Atrypa reticularis,' common forms having a wide vertical 

 range. Associated with them was^the coral Acervularia2}entagona. This was 

 found also by the writer in the Nevada limestone of Treasure Hill,' White 

 Pine, the only other locality where it has been observed in the Great Basin. 



Table Mountain.— Soutli of Browus Canyou the beds of Combs Peak con- 

 tinuing westward graduall)' curve around until the limestones of Table 

 Mountain strike north and south and lie nearly horizontal, but with a slight 

 dip to the east. Table Mountain is made up of dark massive beds, the 

 upper strata occupying about the same geological position as the summit of 

 Temple Peak. From Table Mountain westward to Antelope Valley, the 

 long spurs afford a fair opportunity to study the beds of the lower and 

 middle portions of the Nevada epoch, which is here represented by 2,500 

 to 3,000 feet of limestones. 



Devon Peak.— The Culminating point of the northwest part of Mahog 

 any Hills is known as Devon Peak (8,537 feet), although it is simply the 

 highest point in a broad, plateau-like body of nearly horizontal limestones. 

 To the west and north the beds incline gently toward the sage brush plain 

 of Antelope Valley and the broad plain west of the Pifion Range. One or 

 two of the more deeply eroded canyons offer partial exposures of the beds, 

 but nowhere any continuoi;s sections more than 500 to 700 feet in thick- 

 ness; yet they serve to show similar conditions of sedimentation over a wide- 

 spread area. All over this area, at several horizons, a few scattering 

 fossils may be found, such as Atrypa reticularis, Sfrophomena rJiomhoidalis, 

 Spirifera pinonensis, Stromatopora, and Chcetefes. In the first ravine running 

 up to Mahogany Hills from Hay Ranch Valley, the limestones afford 

 such large numbers of corals, partially weathered out, that the locality 

 would well repay a visit by anyone specially interested in the study of 

 Devonian fauna. 



Yahoo Canyon.— This canyon has its soui'ce at the northern end of Dry 



' IT. S. Oeol. Explor. 40th Par., vol. ii, nesoriptive OeoloKv, p. 544. 



