670 DESCRIPTIVE GEOLOGY. 



apparently much broken uj) and folded ; on the summit of the peak, they 

 dip 30° to 35°, while on the ridge, running out to the southward, recorded 

 dips indicate in one locality 15° and in another 20°. These beds extend 

 from the summit of the peak to the very bottom of Willow Canon in a 

 nearly perpendicular wall, exposing about 1,200 feet of heavily-bedded 

 dark-gray limestones, in places somewhat shaly and of lighter bluish-gray 

 tints. 



At the base of the limstone in Willow Canon were found the following 



Carboniferous forms : 



Productus semireticulatus. 



Produdus Prattenianus. 

 Eumetria pundulffera. 

 Athyris incrassata. 



About 100 feet below the summit of the peak, and separated from the 



last locality by about 1,000 feet of limestone strata, were obtained several 



Carboniferous fossils, but of entirely distinct generic forms. The beds 



yielded : 



Fusilina cylindrica. 



Campophyllum, sp.? 



Organic remains belonging to Carboniferous horizons have been found, 

 within the belt of this survey, in nearly every mountain uplift from the 

 Laramie Hills westward to Battle Mountains, and it is of special interest 

 to note here that the latter is the most westerly mountain group within 

 the limits of the Fortieth Parallel Survey where a development of Car- 

 boniferous rocks has been identified, as from here westward to the Sierra 

 Nevada in California no post-Archsean beds have been recognized as older 

 than the Triassic. 



In the same trend with the limestone belt that skirts the western foot- 

 hills occurs a small body of limestone, lying out in the plain east of Elder 

 Creek, which apparently forms a low dividing ridge between the Humboldt 

 Valley and the valley to the south. This limestone is almost entirely con- 

 cealed beneath the Quaternary detritus, and was only hastily examined. 

 No fossils were found, but it has been, with the other limestones of the 



