714 J. W. BEEDE 
sediments and the Red Beds, the transition between the 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 northeast- 
ward to the easternmost limit of the Red Beds has not yet been 
determined, and indeed may be very difficult to determine, where 
the unconformity would resolve itself to a mere disconformity of 
layers of shales, and perhaps accompanied by a greater or less rework- 
ing 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 Emoria 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,* 
« Bull. Amer. Museum, XXIII, pp. 659-64, 1907. 
