76 THE UNIVERSITY OF OKLAHOMA 



sediments were spread over the entire region. 



Subsequently, during a post-Cretaceous uplift these Cretace- 

 ous sediments were removed and the streams started in the Cretace- 

 ous beds overlaying the plateau were imposed, after erosion of the 

 Cretaceous, upon the underlying folded plateau formations, and thus 

 the valleys now intrenched in the plateau were described by Taff 

 as typical superimposed valleys. 



The writer's interpretation of the physiographic history of the 

 Arljuckles differs from Taff's in ascribing a much earlier date to 

 the degradation of the mountain area to the low relief of a 

 plateau. It is the writer's interpretation that the Arbuckle Moun- 

 tains were reduced to the low features of a plateau during the Car- 

 bonifereous period of degradation which closed with the deposition 

 of the Permian redlied sediments rather than at the much later 

 Cretaceous period of degradation. The writer's interpretation is 

 based upon a more extended study of the character and distribu- 

 tion of the Carlionifereous conglomerates than Taff was able t^^ 

 make. 



While it is difficult to understand fully the reasons for Taff's 

 \ iews, it seems that Taff thought that the erosion of the 10,000 feet 

 of folded Paleozoic sediments of the Arbuckle area at the close of 

 the Carboniferous period of degradation had reached down only 

 to the Arbuckle limestone. This view may have been based upon 

 his belief, as indicated by his description of the Franks Conglomer- 

 ate of Carboniferous age, as containing pebbles and boulders not 

 older than the Arbuckle limestone formation ; or at least he does 

 not mention the occurence of pre-Cambrian pebbles and boulders 

 in the Carljoniferous conglomerates of the Arbuckle region. 



With reference to the relief of the area Taff speaks o: the 

 .\rbuckle Mountains as having been worn down to mountains of 

 moderate relief at the close of the Carboniferous, and a moderate 

 mountain relief, (say an elevation of 3000 to 4000 feet) woiud 

 seem a reasonable assumption concerning the conditions of degrada- 

 tion when the Paleozoic covering the pre-Cambrian had been 

 eroded only some distance into the Arbuckle limestone formation. 



It has been found, however, by a more intensive study of the 

 conglomerate that the later Permo-Carboniferous conglomerates 

 contain abundant pre-Cambrian pebbles and boulders. Thus the 

 constituents of the late Carboniferous sediments clearly indicate 

 that the erosion of the rocks of the Arbuckle Mountains had not 

 only reached entirely through the Arbuckle limestone formation but 

 the erosion had also extended some distance down into the under- 

 lying pre-Cambrian as early as the beginning of the deposition of 



