BULLETIN 612 



GEOLOGIC AND TOPOGRAPHIC MAP 



OF THE 



OTEELAND EOUTE 



From Omaha, Nebraska, to San Francisco, California 



Base compiled from United States Geological Survey Atlas Sheets, 

 from railroad aligMJiieuts and profiles supplied "by the Union Pacific 

 Railroad Company and the Southern Pacific Company and from addi- 

 tional Information collected -vrith the assistance of these companies 



UNITED STATES GEOLOGICAL SURVEY 



GEORCtE OTIS SMITH, DIRECTOR 



David White. Chief Geologist 



B. B. Marshall, Chief Geographer 



1915 



EXPLANATION 



A 



Sand, gravel, and day; fresh-water deposits 



(Arikaree and Gerinj?;: formations) 

 Sandy clay; fresh-water deposit (Brule clay) 

 Sand and travel; fresh-water deposit (Chadron formation* 



Thickness 

 in feet 



20*) -250 



250 



20-100 



Tertiary 



B 



Sanostone. (.conglomerate, shale, and coal; 



fresh- water deposits ("Upper Laramie" and younger 

 formations) 



10.000 



Tertiary- 



possibly including 



some Cretaceous 



C 



J Sandstone; marine deposit (Fox Hills sandstone eastof Sherman) 

 i iiandstone. shalo, and coai; marine and bi-ackish water 

 1^ deposits (Mesavorde formation west of Sherman) 



700-tl 

 2,000 



D 



^ha e: manne depoisit (Pierre shale east of Sherman) 5 000 



bhaie; manne deix>6it Steele shale west of Sherman) 2.500-3,000 



Umestone and shale; marine deposits tNiobram limestone; 325 - 400 

 bhaie; manne deposit (Benton shalej 700- 1 000 



C retaceous 



E 



Sandstone and shale probabiy includes equivalents of Dakota 

 sandstone, Fuson formation, and Ukota sandstone; fresh 

 and brackish water aeposiU (Cloveriv formation i 



I 



0-100 J 



F Sandstone and shale- fresh- water deposit ( Morrison formation) 150 - 200 



Jui*assic or Cretaceous 



6 Sandstone and shale; marine deposit 'Sundance fo: ...ation 



1 



30-60 Jurassic 



H Red sandstone, shale, and gypsum; fresh or brackish 



water deposits tChugwater forn\ation) 



Triassic or 

 1, 100 Permian 



1 



Limestone; marine deposit ( Forelle limestone^ 

 bandy shale and gy]>sum, marine or brackish' water 

 ^ deposits i Satanka shale) 



Limestone and red sandstone: marine deposits 

 (^ (Casper foi-mation. 



800 



0-2(Ti 

 0-230> 



-i.oooj 



Carboniferous 



J Granite, gneiss, schist, igneous rocks (.mainly Sherman granite) 



Pre-Cambrian 



SHEET No. 9 



