THE AGE OF ANTHRACOLITHIC ROCKS 713 
Beds does not occur in Kansas but is found in western Oklahoma 
and the Panhandle of Texas. 
The whole of the lower succession of shales and limestones form- 
ing lowlands and low escarpments divide this section of continuous 
sedimentation into short stratigraphic 
units of great lateral extent convenient 
for paleontologic study. 
In Oklahoma different conditions 
prevailed during much of the time repre- 
sented by the Kansas deposits, above 
the Cherokee shales. 
Passing from Kansas to Oklahoma 
the light-colored shales and limestones 
of the upper part of the Kansas section 
grade off into red shales and sand- 
stones. The lowest horizon in Okla- 
homa at which the red sediments pre- 
dominate is unknown, inasmuch as the 
strike of the rocks is but little west of 
south, and the Red Beds protrude east- 
ward in central Oklahoma as a sort 
of embayment, especially north of the 
Arbuckle Mountains. ea Fae 
In the region south of the western 
end of the Arbuckles the Red Beds he 
unconformably upon the tilted and 
eroded Pennsylvanian rocks. It ap- 
pears that the Albany-Wichita sea of Tex. Okla. Kans. 
northwest Texas transgressed over this 
region during a time of slight depression, the waters covering the 
western end of the Arbuckle Mountains, swinging eastward on 
their northern slope as far as the Seminole Country. According 
to Cummins there is no unconformity in Texas between the lighter 
« For the citation and review of the literature on the Permian of Oklahoma and 
Texas, see the author’s paper on the “‘Invertebrate Paleontology of the Upper Permian 
Red Beds of Oklahoma and the Panhandle of Texas,” Kans. Univ. Sci. Bull., IV, 
pp. 115-48, 1907. The geology of the Arbuckle and Wichita mountains is described 
by Mr. J. A. Taff in Professional Paper 31, U. S. Geol. Surv., 1904. 
