480 



EEPOET UNITED STATES GEOLOGICAL SUEVEY. 



General section of Palceozoic formations in the T4ton district. 



Alternations of more or less arenaceous limestones, sandstones, and gritty shales; 500 

 and less to 1,000 feet. Penno-Carboniferous division of the Upper Carboniferous. 



Alternations of quartzitic sandstones, gray, more or less cherty limestones, and red 

 shaly layers; 1,000 to 2,000 feet. Upper Coal-Measure division of the Upper Carbon- 

 iferous. 



Generally more or less cherty limestone, "with local interpolations of quartzitic sand- 

 stone or siliceous beds, and red arenaceous shales; 1,000 to 2,000 feet, more or less. 

 Lower Carboniferous, includin.^, possibly, several at least locally defined divisions, 

 •which resemble similar epochal divisions in the Upper Mississippi region. 



Heavy-bedded buff magnesian limestone, usually "weathering in castellated exposures; 

 400 feet and less to 600 feet. In the southwest occurs a local development of light- 

 colored, rough-weathered quartzitic sandstone, 50 feet or more in thickness, appar- 

 ently occupying the place of the dolomitic limestones. Also local developments of 

 drab shales, 100 feet, more or less, occur in this horizon. 



Generally even thin-bedded limestones ; 50 to 200 feet. Upper limestone. 



Shales, more or less arenaceous, with thin indurated arenaceous bands and lime* 

 stone layers ; 500 feet and less. Interchangeable with the above occurs a quartz- 

 Ite conglomerate, 50 to 150 feet thick, forming an inter-Quebec horizon of varia» 

 ble local aspect. Passage beds. 



Limestone, usually thia-bedded, in places brecciated, rusty-weathered, but quite 

 variable in local appearance and vertical extent; 50 to 200 feet. Lower lime, 

 stone. 



Arenaceous indurated deposits, rusty and dirty-yellow weathered, and sandstone, 

 sometimes glauconitic, but also white and variable, based upon quartzito, also 

 variable in color, laminated and conglomeritic; 200 to 300 feet, more or lessi 



Quartzites, micaceous and chloritic slates, forming heavy deposits several thousand feet in 

 thickness. Developed in the southwest, but apparently absent in the central and east- 

 em portion of the district. 



Gneisses, various schistose rocks, and granite. 



