BLACKWELDER: new formations in WYOMING 425 



10. Limestone; gray, petroliferous, crystalline. Filled with 



poorly preserved bryozoans and gastropods 7 



9. Dolomite; gray to white, with white chert nodules 14 



8. Sandstone; smoky gray, weathering brown. Contains angu- 

 lar fragments and grains of white chert, and granules of 



cellophane 10 



7. Chert; thin bedded and lumpy, gray to white, with greenish 



shale partings 21^ 



6. Shale; black, slightly phosphatic 8 



5. Phosphorite; soft, crumbling, oolitic; passing upward into 



shale 4 



4. Breccia; fragments of chert imbedded in a brown phosphatic 



matrix, resting on a sharp irregular surface 2 



Tensleep sandstone 



3. Dolomite; light gray, with nodules and laminae of gray chert 4 



2. Sandstone; white, pitted, calcareous 2 



1. Sandstone; creamy white, weathering light brown to pink 



about 300 



DINWOODY FORMATION 



The upper part of Barton's Embar formation consists in this 

 region of greenish-gray shales, with many thin plates of dense, 

 calcareous sandstone, or argillaceous dolomite, which weathers 

 bro"\vn, tawny, and even black. This portion — which is to be 

 distinguished from the lower or Park City portion of the Embar — 

 is 250 feet thick at Dinw^oody Creek on the north slope of the 

 Wind River Range, but thins down to less than 50 feet near 

 Lander. In the Owd Creek Mountains it is 75 to 100 feet thick 

 near Anchor. Eastward, near Thermopolis, the formation be- 

 comes gypseous, and more or less reddish in color. Mr. D. Dale 

 Condit^ has traced it into the Bighorn Range, where it merges 

 with the lower part of the Chugwater red-beds. Westward it 

 becomes progressively thicker, more calcareous, and more fossilif- 

 erous, and changes by imperceptible gradations horizontally into 

 the Woodside and Thaynes formations of southeastern Idaho. 

 It is about 210 feet thick on Crystal Creek in the Gros Ventre 

 Range, 350 feet thick at the north end of the Hoback Range, 

 and thence into Idaho it rapidl}^ increases in volume. 



The Dinw^obdy formation is conformable both above and below. 

 Although some beds contain abundant Lingulas and poorly pre- 



9 CoNDiT, D. Dale, U. S. Geol. Survey Prof. Paper 98-0. 1916. 



