THE BASIN PROVINCE 



169 



"A mile north of this locaHty there is a similar section, but the basal limestone 

 is thinner, not over lo feet thick, is yellowish in color in its lower portion, and lies 

 directly on the Tensleep sandstone. At the western entrance of the deep canyon, 



4 miles north of No Wood, the top limestone underlying the Red Beds is 12 feet 

 thick, massive, cherty, impure, and of yellow color. Next below are 40 feet of 

 shales and soft sandstones, partly pale red, but yellowish near the top. They 

 contain a few layers of limestone and lie on the Tensleep sandstone. On the 

 east slope of Bighorn Mountains the formation appears at intervals in the valley 

 of Buffalo Creek, near the Hole-in-the-wall. The limestone is 20 feet thick, 

 with a 2-foot massive layer at the top, and with thinner-bedded slabby limestones 

 of greenish-gray color and green shale below, lying on the Tensleep sandstone. 

 The formation is traceable continuously northward to the Red Fork of Powder 

 River, but gradually thins in that direction. On the anticline in Red Fork Valley, 



5 miles northeast of Barnum, the Tensleep sandstone is overlain by a thin mass 

 of limestone breccia, merging up into 6 feet of buff sands and greenish shale, 

 which probably represent the northeasternmost extension of the Embar forma- 

 tion." 



Blackwelder,! as already indicated, has suggested the equivalence of 

 certain beds in eastern and western Wyoming. The Tensleep of the Big- 

 horns is the same as the Weber of Utah and the southwest; the Embar is 

 the equivalent of the Park City; the Morgan formation of Utah is the 

 equivalent of the Amsden of the Bighorns. In the Gros Ventre Range 

 the phosphate beds become cherty and unfossiliferous. Toward the Wind 

 River Range, Shoshone, and Owl Creek Mountains the phosphate thins and 

 deteriorates and beds exceeding a few inches in thickness do not occur north 

 of the Owl Creeks, northeast of the north part of the Bighorns northeast 

 of the low ranges between Casper and Lander. 



Condit.in a recent paper,^ gives a description of the Phosphor ia formation 

 in Wyoming and Montana, with a map showing the distribution of the Phos- 

 phoria and Embar formations and a series of stratigraphic sections. He 

 says (page 113): 



"The Quadrant proper is overlain by 100 to 250 feet of dark-gray cherty 

 quartzite, layers and ropy masses of nodular chert and shale. The sequence is, 

 regarded as equivalent to part of the Park City formation of Utah and Wyoming, 

 but more nearly equivalent to the Phosphoria formation of Idaho, as was recog- 

 nized in 1913 by Richards and later by Stone and Bonine. * * *" 



"The uppermost beds of the Phosphoria contain poorly preserved brachiopod 

 shells and fish bones, probably of Permian age." 



> Blackwelder, Eliot, A Reconnaissance of the Phosphate Deposits of Western Wyoming, 

 U. S. Geological Survey Bull. No. 470, p. 458, 1910. 



^Condit, D.D., Relations of the Late Paleozoic and Early Mesozoic Formations of South- 

 western Montana and Adjacent Parts of Wyoming, Professional Paper No. 120-F, U. S. 

 Geological Survey, 1918. 



