go THE PERMO-CARBONIFEROUS RED BEDS OF 



The deposits of Rio Arriba County certainly extend west under the Creta- 

 ceous and Tertiary of northwestern New Mexico into Arizona, where they 

 reappear as the Moencopie and Kanab (?). Permian or Permo-Carbonifer- 

 ous invertebrate fossils have been found in limestones in northern Utah and 

 as far north as the Bighorn Mountains. The limestones are apparently con- 

 nected with the Red Beds of New Mexico and Arizona in somewhat the same 

 way as the limestones of the Plains Province are connected with the Red Beds 

 there. It is possible, even probable, that the deposits of the Basin Province 

 were formed somewhat earlier than those of the Plains Province, but both 

 were laid down within the limits of the Permo-Carboniferous. 



I am inclined to suggest some changes in Schuchert's paleogeographic 

 map of the lower Permian (Permo-Carboniferous) . It is increasingly evident 

 from a study of the Red Beds that there was a land-mass of great size and 

 height between the two areas of land deposits on the eastern and western 

 sides of the Rocky Mountains. No attempt has been made in the present 

 paper to determine the amount of material included in the portion of the 

 Red Beds considered as Permo-Carboniferous in age, but the briefest inspec- 

 tion reveals an amount of material so great that it can have originated only 

 in the degradation of a mass of land far larger than the present igneous and 

 early Paleozoic rocks in the Rocky Mountains, and if we add to the Permo- 

 Carboniferous deposits those of Pennsylvanian, Triassic, and Jurassic age 

 which are with difficulty distinguished or are evidently the result of a con- 

 tinuation of similar conditions, the mass of the land later degraded assumes 

 majestic proportions, for it is easily demonstrable that the source of by far 

 the largest proportion of the Red Beds material was the land-mass on the 

 present site of the Rocky Mountains. 



In the Plains Province the conditions for land deposition shaded into 

 limestone-forming seas to the east and northeast; that these seas were nar- 

 row from east to west there can be no doubt, because of the high land of 

 Ozarkia and the land deposits in Iowa, which show an elevation, but they 

 were sufficiently broad to prevent the transportation of any material from 

 the eastern land to the flats where the Red Beds were formed. 



The outline of the Red Beds west of the Rocky Mountains is not yet 

 clearly made out, but the land deposits are more closely associated with 

 limestones both vertically and horizontally, indicating shorter duration and 

 lesser extent, with a closer approximation of the ocean waters to the great 

 land-mass than in the east. 



The Wichita Mountains and the Arbuckle Hills were only subsidiary 

 sources of supply. It is probable that much of the material of the Red Beds 

 in Arizona came from sources not yet clearly imagined; however, there is 

 evidence that the Rico was deposited near the source of the material, and the 

 distance from Ouray to the Grand Canyon is not greater than from the Front 

 Ranges of the Rockies to some localities of Red Beds in Kansas. 



