76 THE PERMO-CARBONIFEROUS RED BEDS OF 



widespread formation in southern Colorado, Arizona, and western New 

 Mexico, its absence at all points east in the same latitudes is of considerable 

 significance. 



The limits of the Basin Province are less certain than those of the Plains 

 Province, but it is certain that the area of Red Bed deposition of Permo- 

 Carboniferous time covered northern Arizona and New Mexico and extended 

 north through western Colorado into Wyoming. Its western side seems to 

 have terminated in a limestone-forming sea coveiing the site of the Uintah 

 and Wasatch Mountains, and its eastern side rested against the land-mass 

 which sepai-ated it from the Plains Province. 



Opposed to the proposition of a separate (Basin) area of deposition is the 

 discovery by Weeks '^ of certain fossils on the southeast slope of Hamcl's Peak, 

 some miles south of Ely, Nevada, which Girty determined and regarded as 

 of a "similar fauna to that of the Marion formation of the Kansas section, 

 which Prosser regards as a Lower Permian fauna, and it can probably be 

 safely correlated with the Marion." The list is: 



Productus sp. Bulinwrpha pcracnta. 



Nuciilana cf. obesa. Murchisonia, near marcouiana. 



Plcurophorus? sp. Bdlcrophon sp. 



Schizodus sp. Dimatoceras sp. 



Straparollus catilloides. Ostracoda. 



Pleurotimaria humerosa. Bakewellia parva. 



The lowest beds observed in Arizona and New Mexico, San Jose region, 

 occtir in the axis of an anticline 8 miles west of Rio Puerco Station, 20 feet of 

 greenish-gray shales with thin sandstone layers and an inch of coal at top. 

 Fossils from this locality are given by Darton'' as: 



Myalina perattcnuata. Bakewellia (?) sp. 



Myalina penniana. Btdlimorpha, near B. nitidida. 



Aviculopecten cf. A. whitei. Spirorhis sp. 



These are related to the Permian fauna of the Mississippi Valley. 



Keyes'^ says that red beds of the Bernalillo shale nearly 1,000 feet thick 

 occur in the Sandia Mountains above the dark-blue and black limestone 

 and carry abundant fossils which "correspond faunally with those found in 

 the upper part of the Oklahoman scries of Kansas." He refers to the Report 

 of the Governor of the Territory of New Mexico to the Secretary of the 

 Interior, page 339, 1903. This report docs not mention fossils in the Bernalillo 

 shale, but does in the blue and black limestone beloiv, referring them to 

 Carboniferous of the Mississippi Valley. 



The evidence here cited is not sufficient to raise a great objection to the 

 existence of separate basins of deposition. It is very possible that there may 

 have been short and local extensions of the seas of the Plains Province to 

 the west. 



" Spurr, Bull. U. S. Geological Survey No. 208, p. 52, 1903. 

 ^ Darton, U. S. Geological Survey, Bull. 435, p. 37, 1910. 

 " Keyes, Iowa Acad. Sci., vol. 15, p. 144, 1908. 



