270 J. E. SPUKR — ORIGIN AND STRUCTURE: OF THE BASIN RANGES 



Plate" 25. — Cross-sections of typical Basin Ranges 



Figure 1. — East-west section of Qiiinn Canyon and Grant ranges. 



Advanced stage of ascendency of erosion over deformation. Syncli- 

 nal ridges and anticlinal valleys of erosion. Scale, 1 inch =abou'i 

 32 mile?. 

 l=:Cambrian limestones; 2 — Pogonij) limestone (Silurian); 3 = 

 Eureka quartzite (Silurian) ; 4 = massive limestones, probably in- 

 cluding both Silurian and Devonian ; 5 =-. intrusive granitic rocks ; 

 6 = extrusive rhyolites ; 7 — valley wash (Pleistocene). 



Figure 2. — East- west section of Spring Mountain range. 



Ascendency of erosion over deformation. Synclinal ridge of erosion. 

 The strata in this figure are massive limestones, chiefly Carbonif- 

 erous, but very likely with Devonian and ))Ossibly Silurian in the 

 lower portions. Scale, I inch =: about 3^ miles. 



Figure 3. — North-south section of Spring Mountain range. 



Advanced stage of ascendency of erosion over deformation, with 

 probable recent deformation superadded. Slight normal erosion 

 fault-scarp; fault with no eflect on topography; probable later 

 anticlinal arch of deformation. Scale, 1 inch = al)out 30 miles. 



1 :=r Cambrian quartzites chiell\'; 2 = C^imbrian limestones; 3 = 

 Silurian limestones ; 4 = mjissive limestones, chiefly Carboniferous, 

 but very likely extending through the Devonian into the Silurian, 

 possibly into tlie Cambrian ; 5 — valley wash (Pleistocene). 



FiGUKE 4. — East- west section of Mormon range 



This section is taken at the northern end of the range. Ascendency 

 of deformation over erosion. Anticlinal ridge of defoimation, 

 bearing a growing anticlinal valley on its crest. Scale, 1 inch =- 

 about 3.] miles. 



1 = Carboniferous limestones; 2= chiefly ancient folded acid vol- 

 canics and derived sediments (early Tertiary) ;• 3 ^ little folded 

 conglomerates and sandstones, with lavas (late Tertiary-Pleisto- 

 cene). 



Figure 5. — East-west section of Hot Creek range. 



This section is taken at Hot creek. Special relation of deformation 

 and erosion. The deformed strata have been i)rotected from ero- 

 sion l)y a covering of lava, only lately stripped off in jilaces.. 

 Probable anticlinal ridge of deformation, and simple fault-scar])s 

 (a, c). Erosion fault-gulch (/>). 



l=Pogonip limestone (Silurian); 2 = Eureka quartzite (Silurian); 

 3 = Up|)er Silurian shales and tiiln ])ed(led limestones, correspond- 

 ing to the Lone Mountain formation of pAireka ; 4 — massive 

 rh\'olite; 5 = stratified older gravels (Pliocene) ; 6 = valley wash 

 (Pleistocene). 



