CARBONIFEROUS SYSTEM 417 



Next below are alternations of limestone and sliale, 25 feet or more in 

 tliiekness, lying on a thin deposit of sandstone breccia, which in turn lies 

 on Tensleep sandstone. At the foot of the mountain slope the limestone 

 member is seen to pass imder 3'ellowish sandy beds containing a few thin, 

 impure layers of limestone, in all from 50 to 60 feet thick. Near North 

 fork of Muddy creek, where the total thickness is 250 feet, the 50-foot 

 limestone is overlain by nearly 100 feet of shale containing a large amount 

 of nodular chert and a thinner massive limestone. Toward the top tlie 

 beds are sandy and in most places of a Ijright yellow color. In the anti- 

 cline on the south side of the mountains, 2 miles east of longitude 109°, 

 the following section was measured : 



Section of Emhar Formation near Muddij Creel; 2 Miles East of Longitude 



109° 



^^-^ Feet 



Compact gray sandstone, weathering brown, merging down- 

 ward into brownish gray and yellowish soft sandstone... - 00 



Light colored massive limestone 30 



Nodular dark colored limestone, in part clierty 80 



Dark gray fossiliferons sandstone 4 



Light buff colored soft sandstone, with layers of limestone, 



lying on Tensleep sandstone GO 



Total ; 224 



In the vicinity of Eml:)ar the massive limestone memljer is 50 feet 

 thick, and near Anchor post-office it is overlain by 25 feet of soft butf 

 sandstone. On Dry creek, 6 miles northeast of Black mountain, the 

 formation is much thicker than observed in other places. The Imsal 

 sandstones and limestones thicken to 200 feet, while the limestone mem- 

 ber elsewhere near the top of the formation is 30 feet thick and overlain 

 by over 200 feet of slabb}^ brown sandstones, with some layers of buff soft 

 sandstone. The latter extend to the base of the Chugwater red l)eds. 



Wind River mountains and eastward. — Near Sage creek, on the north 

 slope of "Wind Eiver mountains, the Embar formation presents the follow- 

 ing beds : 



Section of Enihar Formation West of Fort Washakie, Wyoming 



Feet 



Shaly limestone 2 



Yellow shale 25 



Sandstone 4 



Yellow shale 7.T 



Limestone, cherty in upper and lower parts ; many fossils. . 30 



Yellow shale 40 



Limestone (on Tensleep sandstone) 10 



Total 18G 



