GEOLOGIC DIVISIONS MAPPED. 11 



Content: Marine and coastal-plain deposits of the Atlantic and Gulf coasts and West Indies, 

 comprising Raritan to Manasquan, New Jersey; Black Creek ("Bladen") and Peedee 

 ("Burches Ferry"), North Carolina; Tuscaloosa to Ripley, Alabama; and the Gulf series 

 (Woodbine to Navarro) of Texas and Louisiana. In Mexico, included on map with Lower 

 Cretaceous (8). Marine and coastal-plain deposits of the Interior, Dakota to Fox Hills, 

 inclusive, and equivalents. Marine deposits of the Pacific coast, Chico and its equivalents. 

 Laramie and coal-bearing portion of the Montana of the Rocky Mountains and Great 

 Plains mapped separately. 



MONTANA, COAL-BEAEING POETION. 



Color, ohve-green. 



Symbol, 7a. 



Distribution: Rocky Mountains and northern Great Plains of the United States and Canada. 



Content: Middle Montana, generally coal bearing; Mesaverde of New Mexico, Colorado, and 



southern Wyoming; Eagle, Claggett, and Judith River of northern Wyoming and Montana, 



and their equivalents in Canada. , 



LOWER CRETACEOUS. 



Color, medium green. 



Symbol, 8. 



Distribution: Atlantic, Gulf, and Caribbean coasts, New Jersey to South America; Pacific 

 coast, Alaska to South America. In Mexico, areas mapped include Upper Cretaceous. 



Content: Potomac group of the Atlantic slope, Georgia, and eastern Alabama; Comanche series; 

 (comprising Trinity, Fredericksburg, and Washita groups) of Texas, Oklahoma, and 

 Mexico; Shasta series (Knoxville and Horsetown formations) of California and Oregon; 

 Queen Charlotte group of British Columbia; Kootenai formation of the Rocky Mountains, 

 Montana northward to fifty-second parallel and beyond; Lower Cretaceous, Alaska. 



TRIASSIC AND JURASSIC. 



Color, dark greenish blue. 



Symbol, 9. 



Distribution: Middle western United States, Rocky Mountains, and High Plateaus, Montana 



to Arizona; western United States and eastern Alaska, where Triassic and Jurassic can 



not be separated or can not be separately identified. 

 Content: Red beds and marine deposits of the Cordillera, comprising Jurassic, Triassic, and 



Permian, where more or less certainly known to be present but not distinguishable, or too 



small to map separately; marine Triassic and Jurassic of the Pacific where not separated. 



JURASSIC. 



Color, greenish blue (horizontal ruling). 



Symbol, 9a. 



Distribution: Central America, Mexico, California, Oregon, Alberta, and parts of Alaska. 



Content: Jurassic limestone and shale of Nevada; Mariposa slate. Sierra Nevada; Franciscan 

 formation. Coast Range, CaUfornia; Jurassic of Mexico; Chinitna shale and Tuxedni 

 sandstone ("Enochkin formation"), also the Naknek formation, of Alaska Peninsula. 

 The Jurassic of the Humboldt Range, Nevada, and the marine Sundance formation of the 

 Rocky Mountains are not distinguished on the map from Triassic, as the areas are too 

 small to distinguish the system separately. 



TRIASSIC. 



Color, dark green (horizontal ruling) . 

 Symbol,. 10. 



Distribution: Central America, Mexico, New Mexico, and Texas; Nevada and CaUfornia; 

 British Columbia and Alaska; Atlantic slope from North Carolina to Nova Scotia. 



