612 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



General section. 



i 

 © 



© 



©* 



fe 



© 



s 

 © 



ID 



h 







Drift. 



? 



2,815 + 



QUATERNARY. 



Salt River conglomerate. 



! 



Malade Valley Group. 



! 



Cache Valley Group. 



o 



CO 



Marsh Valley Group. 



IO 

 CO 



Gentile Valley Group. 



? 



P3 

 H 



Pliocene ? 



Salt Lake Group. 



+ 



o 

 o 



Miocene ? 



Bridger Group. 

 Green River Group. 



+ 



o 



» 



Wahsatch Group. 



+ 



o 



POST CRETA- 

 CEOUS. 



Laramie Group. 





4,000 + 



CRETACEOUS. 



Eox Hills Group. 

 Colorado Group. 

 Dakota Group. 



+ 



o 

 o 

 o 



8,500 + 



< 



H 



<i 

 Ph 

 P 



1-3 



Jurassic. 



Belemnites Beds. 

 Pentacrinus Beds. 



+ 



o 

 o 



Triassic ? 



Red Beds. 

 Meekoceras Beds. 



+ 



o 



O 



o 







N 

 © 



s 

 © 



- 



CARBONIFER- 

 OUS. 



m 

 Carboniferous 1 limestones. 





6,000 + 

 0,810 + 



DEVONIAN ? 



UPPER 

 SILURIAN ? 



LOWER 

 SILURIAN. 



s 



J 



Quebec. 

 Calciferous. 



+ 



o 

 o 



oo 



5* . 



11 



g-S 



Potsdam Cambrian quartzites. 

 Acadian Cambrian slates. 



I 



ARCH^3AN. 



Huronian ? 



O 

 IO 



Granite. 







Total thickness of sedimentary formations 



31, 125 + ft. 



