90 ENVIRONMENT OF VERTEBRATE LIFE, ETC. 



Albany and the Wichita being a gradual lateral one. The transgression of the 

 Red Beds in the Arbuckle Mountains may, then, be regarded as a northeastern 

 or eastern encroachment of the Wichita sea — or conditions of sedimentation, 

 as all these beds may not be marine. Whether this Arbuckle unconformity 

 extends northeastward to the easternmost limit of the Red Beds has not yet been 

 determined, and indeed may be very difficult to determine, where the uncon- 

 formity would resolve itself to a mere disconformity of layers of shales, and 

 perhaps accompanied by a greater or less reworking of the lower deposits. 

 Gould, who has been over this region between the Arbuckles and the Arkansas 

 River many times, states that he knows of no unconformity. If no unconformity 

 exists to the north of the Arbuckle Mountains, it seems probable that the first 

 Permian emergence began here and the deposition of the red beds in the Seminole 

 country is the first record of it, the later sediments from the Arbuckles reaching 

 farther north. Regarding the gradation of the upper part of the Kansas section 

 into the Red Beds in northern Oklahoma, there can be no doubt whatever, and 

 the same is probably true of the central part of the State. 



"The Arbuckle and Wichita mountains are probably the source of much of 

 the red sediment in which they are partially buried, and the former mountains 

 are directly responsible for the eastern extension of these beds into central 

 Oklahoma. The extent to which the lighter-colored sediments of Kansas and 

 Texas are replaced by red sediments in Oklahoma and near it represents in a 

 rough way the limits of the influence of these mountains on the deposits of the 

 time by the spread of their sediments. By the time the deposition of the light- 

 colored sediments had ceased the conditions had become such that nearly all 

 the sediments derived from the land surrounding this basin were red. 



"In the Oklahoma region the deposition of red sediments began, perhaps, 

 as low as the Howard or Topeka limestones, and perhaps as high as the Emporia 

 or Americus limestones. The deposits then seem to be uninterrupted until the 

 unconformity below the Dockum beds (Triassic) in the Texas Panhandle is 

 reached. Some of these beds appear to be of subaerial origin, as has been shown 

 by Case, while others are certainly marine. Careful petrologic study will prob- 

 ably demonstrate that much of the arenaceous material is windblown sediment, 

 more or less reworked by currents or waves as the regions were submerged or 

 flooded. That the sea ever covered the entire area from Kansas to southern 

 Texas and New Mexico at one time may be questioned. If it did, the sediments 

 contained were of such a nature and abundance, or the waters so concentrated, 

 as to preclude the free migration of a normal marine fauna throughout the basin. 

 That marine conditions prevailed, at least locally, is demonstrated by the White- 

 horse and Dozier faunas. 



"In Texas normal deposits were laid down In higher horizons than in Okla- 

 homa, and in Kansas there are reasons for believing that the light-colored 

 sediments were laid down at an even later date than in Texas. These conditions 

 are illustrated in the subjoined table, showing a vertical section of the Carbonifer- 

 ous and Permian rocks of the three States. 



"The extent of this post- Pennsylvania basin seems to have been very great. 

 It included much of Kansas (two-thirds), western Oklahoma, much of western 

 Texas, and all of New Mexico, Colorado, and Wyoming east of the Rocky Moun- 

 tain axis. In area it probably aggregated 300,000 square miles. 



"Together with the varied physical conditions of these three regions went 

 corresponding faunal peculiarities. In the Albany division of the Texas rocks 



