154 



REPORT UNITED STATES GEOLOGICAL SURVEY. 



TABLE OF FOEMATIONS. 



A table has been prepared enumerating - tlie various formations and 

 groups as found in the Sweetwater district. The thickness of groups 

 have been given from the minimum to maximum, and it has been indi- 

 cated in which portion of the district the latter is found. Generic names 

 of the fossils observed have been introduced. 



Table enumerating the various formations and groups as found in the Sweetwater district. 



O 





 H 

 

 N 



© 



a 



a 



o 



B 

 o 



pj 



1 



P5 



H 



•4) 

 1=1 



_o 



'P 



P 



K 

 H 

 Ph 

 Ch 

 P 





Fossils. 



Character of strata. 



.9 



03 



M O 



a 







Sand dunes, soil, loose drift and gravel . . 5 



Vary- 

 ing. 



H 



is 

 q 





Shells of living Gasteropods in 

 lake beds. 



Lake beds, glacial deposits, and old river 

 drift. 



Vary- 

 ing. 



3 



PS 



m 



H 



H 

 o 



o 



P4 



s => 









Loose, structureless conglomerate. Spread 

 over the undisturbed younger beds. 



10 

 to 

 400 



8 



.O O 



Numerous remains of Mam- 

 mals. 



White, light yellow, pink, and greenish 

 marls and sands. Some beds of sand- 

 stone near base. 



300 

 to 



900 



a 

 is 

 a 



O 



o 







Local deposit. Brown indurated shales 

 and marls, some sandstone and conglom- 

 erate near base. 



1200 

 to 

 1400 



•5 ° 



Numerous remains of Turtles, 

 Limnce, &c. 



White, light gray, and buff calcareous 

 shales and marls ; series incomplete. 



500 



5» 



Fishes and Insects in shales. 

 Plants higher up. 



Brown, concretionary sandstones near top. 

 Blue, gray, and white calcareous shales 

 lower down. Carbonaceous shales, sand- 

 stones, and dark shales near base. Thin- 

 ning northeast. 



1700 

 to 

 1800 



H 

 W 



o 



o 



1 



Leaves in the sandstones and 

 some of the shales. 



Massive sandstones and shales. Bed near 

 top. Shales yellow and brown, contain- 

 ing selenite. Basalt breaking through 

 them. Coal. 



600 

 to 

 650 



8 



g 









Highly arenaceous marls. White, yellow, 

 green, red, brown, and maroon. Sand- 

 stones near base, together with heavy 

 local conglomerates. Thinning out north- 

 ward. 



600 

 to 

 700 



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