OKLAHOMA ACADEMY OF SCIENCE 11 



the Permian redbeds series. 



Furthermore, the latest of these beds of Permo-Carboniferou'^ 

 conglomerate containing the pre-Cambrian pebbles and boulders 

 lie in the valleys within the plateau area and have such gcnile 

 slopes extending up to the low summit of the plateau as to indicate 

 that degradation of the mountains to a low plateau had already 

 l)een acquired when these valleys were formed. 



It is the interpretation of the writer, therefore, that not only 

 had the low plateau features of the Arbuckle Mountains been 

 acquired, but that the plateau itself was deeply intrenched by valleys, 

 much as it appears today, by the close of the Permo-Carboniferous 

 period of degradation. 



Although Cretaceous sediments overlie the lowest slopes of 

 the southeastern part of the Arbuckle Mountain area there are no 

 outlying remnants of the Cretaceous far beyond the border and it 

 is the belief of the writer that the Cretaceous never extended more 

 than a few miles beyond the present exposed boundary of the for- 

 mation as shown on maps. 



The Arbuckle area and the surrounding region, where the Per- 

 mian occurs seems to have been a land of low altitude most of the 

 time since the close of the Permian as indicated by the relatively 

 low reliefs, of only a few hundred feet which have been sculptured 

 out of the Permian sediments, adjacents to the Arbuckle Mountain 

 area. 



The Arbuckle uplift with other similar uplifts in the surround- 

 ing region were the source of abundant sediments that were laid 

 down in basins surrounding the uplifted areas in Permo-Carboni- 

 ferous times. Many of the uplifted areas were later buried by 

 Permian sediments in the general degradation of the region and are 

 now found as buried hills by the drilling of wells. It is quite 

 probable that the large Ar.buckle Mountain area and likewise the 

 large Wichita Mountain area were never completely covered either 

 by Permian or by Cretaceous sediments. 



XXXIV. SOME OBSERVATION ON EROSION AND 



TRANSPORTATION IN THE WICHITA MOUNTAIN 



AREA 



Oren F. Evans 



From the Oklahoma Geological Survey and the Department of 

 Geology of the University of Oklahoma. 



In the Wichita Mountain area the processes of disintegration 

 and decomposition are working faster than erosion and transporta- 

 tion. The igneous mountains usually have steep, even slopes with 



