kxduch.] SWEETWATER DISTRICT TABLE OF FORMATIONS. 



155 



Table enumerating the various formations and groups, §-c. — Continued. 



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Fossils. 



Numerous Leaves. Inverte- 

 . brutes of fresh- water and 

 brackisk-wate.r types. Os- 

 trea, Yiviparus, TJnio, Goni- 

 obasis, &c. 



Character of strata. 



Series of shales and'sandstones. Coal near 

 the top and near base. Clays and shales 

 in vicinity of coal. Thinning out north- 

 ward, and incomplete there. • 



1600 



^r 



Inoceramus, Ostrea, and nu- 

 merous other Invertebrates. 



Sandstones and shales near the top, con- 

 taining coal. Massive arenaceous and 

 micaceous shales lower down. Shales 

 and sandstones at base. Thinner north- 

 ward. 



Inoceramus, Ostrea, and other 

 Invertebrates. 



Sandstones at top. Massive dark - gray 

 shales, weathering light gray and white. 

 Carbonaceous shales. Thinner toward 

 north. 



500 

 to 

 1300 



COO 

 to 

 850 



Leaves, G-ryphcea, Inoceramus, 

 and other fossils. 



Massive yellow and white sandstones, with 

 carbonaceous shales. Gray, yellow, and 

 brown shales. Sandstones and conglom- 

 erates near base. Thinner northward. 



600 

 to 

 700 



Belemnites, G-ryphcea, Pecten, 

 and other Invertebrates. 



White, yellow, pink, and light-green marls 

 at top. Yellow shales, with limestones, 

 lower down. Massive blue limestones 

 near base. Thicker north. 



120 



to 

 220 





to 



7, 



a 



d 



K 



« 



p 



H 



H 





« 



Natica in dolomitic limestones. 

 Fucoid forms in sandstones. 



White, yellow, and pink coarse-grained 

 sandstones. Thin beds of shales be- 

 tween them. 



3 



s 



S 



g I Indistinct remains of Plants. 



Massive red argillaceous sandstones. Red 

 shales, with dolomitic limestones, in the 

 middle. Red and pink sandstones, with 

 gypsum, near base. Thicker northward. 



Pink and yellow sandstones, with yellow 

 and greenish shales. Ripple-marks. 



150 

 to 

 400 



p 





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o 







fa 



H 



•■£& 



fa 



a 



•s'S 



M 



a 





K 





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£3 







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2 











&S 





o 

 i-i 



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to 







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Productus, Orthoceras, OrtJiis, 

 and other fossils, all silici- 

 fied in the northern portions 

 of the district. 



Massive blue limestone, containing large 

 quantities of concretionary silica. To- 

 ward the base some magnesian lime- 

 stones. Thicker toward the north. 



600 

 to 

 800 



150 

 to 

 320 



1400 

 to 



2200 



Crinoids, Corals, Chonetes, 

 Spirifer, OrtJiis, Orthoceras, 

 Productus, and others, most- 

 ly silicified. 



Dolomitic limestones, yellow and gray dol- 

 omites, with some sandstones near top. 

 Thicker northward. 



350 

 to 

 700 



