420 GEOLOGY OF NORTHWESTERN TEXAS. 



In the northern part of the State, where the Wichita Beds rest upon the 

 Cisco Beds of the Coal Measures, there is as great a difference in the fauna 

 as there is at the other locality. The Cisco Beds are principally sandstones 

 and yellow clays with a characteristic Coal Measure fauna. Immediately upon 

 these beds come the bluish sandstones and red clay beds of the Permian with 

 its fauna. It must be remembered here also there is no continuous sedimenta- 

 tion, for the Albany Division of the Coal Measures comes between these beds 

 in time, and these Albany Beds are about eleven hundred feet thick. The 

 stratigraphic evidences that these two formations are different is very strong 

 in Texas. If we take the Wichita Division of the Permian, which are 

 entirely composed of sandstones and red clay beds, and place them where 

 they rightly belong in point of time, upon the Albany Division of the Coal 

 Measures, which are composed almost entirely of limestones and yellowish 

 clay beds, the contrast between them will be much more apparent than it now 

 appears, with the Clear Fork Division, whose bases are limestones and bluish 

 clay beds, resting directly upon the limestone and clay beds of the Albany 

 Division. 



So far in this Report I have been considering the question whether the beds 

 I have called Permian are capable of being separated distinctly and definitely 

 from those of the Coal Measures, and I think that it has been shown that 

 such can very readily be done in Texas, both on stratigraphic and paleon- 

 tologic grounds, and I think that it is entirely safe to say that the beds do 

 not belong to the Coal Measures series. 



DIFFERENCE BETWEEN THE PERMIAN AND TRIASSIC. 



The next question to be considered is as to how much of the Red Beds in 

 Texas ought to be included in the Permian series. In other words, where 

 ought the line between the Permian and Triassic be placed. I have placed 

 all the strata, as I say in another place, between the Albany Division and the 

 Dockum Beds in the Permian. The Albany Division is the highest part of 

 the Coal Measures in Texas, as I understand it, and the Dockum Beds are the 

 lowest Triassic, as the facts indicate to me. 



Dr. White saw only the Wichita and lower part of the Clear Fork Beds, 

 and from my description of the country thought that my Upper or Double 

 Mountain Beds might be Triassic, but says: 



"Along the western boundary of the Texas Permian, as it has been indi- 

 cated in a previous paragraph, a series of strata about two hundred and fifty 

 feet in maximum thickness, now generally known as the 'gypsum bearing 

 beds' and thought by many to be of Triassic age, rests conformably upon the 

 Permian. In general aspect, in a prevailing reddish color, and in general 

 lithological character, except in the prevalence of gypsum in many of the lay- 



