Adams — Carboniferous and Permian Age, etc. 383 



Art. XLII. — The Carboniferous and Permian Age of the 

 Red Beds of Eastern Oklahoma from IStratigraphic Evi- 

 dence ; by G-eokge I. Adams. 



[Published by permission of the Director of the U. S. Geological Survey.] 



Various opinions have been expressed from time to time 

 concerning the age of the Red Beds of Oklahoma. By some 

 they have been called Triassic and by others Permian, but 

 because of the general absence of fossils and the lack of strati- 

 graphic work they have remained an uncertain group. Collec- 

 tions of fossils made by C. 1ST. Gould at White Horse Springs, 

 sixteen miles west of Alva, from the Red Bluff formation of 

 Cragin, situated one hundred feet or more above the gypsum 

 ledges, have been determined by Schuchert and Beede as Upper 

 Permian forms. * Vertebrate remains from Orlando in Logan 

 County and from Hardin in Kay County, although not fully 

 studied, are considered by S. W. Williston as equivalent to 

 Cope's Lower Permian fauna from the Wichita beds of Cum- 

 mins in northern Texas.f The writer has recently done some 

 stratigraphic work which has a direct bearing on the problem 

 of the Red Beds, and it is believed that it supplies a correct 

 interpretation of the beds and furnishes a basis for future 

 detailed study of them. 



In tracing the outcrops of the limestone formations of the 

 Carboniferous of Kansas, the writer observed that in going 

 southward there is a gradual transition in the character of the 

 sediments to those which are more arenaceous, and that there 

 is a thickening of the shales and sandstones and a thinning and 

 final disappearance of some of the limestones. Moreover, in 

 describing the shales of the higher portion of the Carboniferous 

 and the lower portion of the Permian, the occurrence of 

 purplish and maroon colored shales was noted. The signifi- 

 cance of these observations was not fully known, since the work 

 of the Kansas survey was limited by the State line. In study- 

 ing the oil and gas fields of Kansas and Indian Territory,:): the 

 writer traced to the southwestward the extension of the out- 

 crop of the Fort Scott limestone from the southern border 

 of Kansas into Indian Territory. It extends from west of 

 Chetopa in Kansas to Chelsea, Claremore and Catoosa, and 

 thence to the Arkansas river west of Weer, when it becomes 

 inconspicuous. The horizon as marked by the associated sand- 

 stones was followed to a point between Holdenville and 



* Amer. Geologist, vol. xx. No. 1, p. 46. 



+ Article not yet published. 



X Forthcoming Bulletin U. S. Geol. Survey. 



