The Permo-Carboniferous of Northern New Mexico

Abstract

The age of the Red Beds of the Rocky Mountain region has long been in doubt. They outcrop extensively along the eastern foothills, extending across Wyoming from the Laramie Mountains to the Wind River Range, thence through eastern Utah and western Colorado, with extensive exposures in the southwestern part of that state; in various places in northern New Mexico, from the San Juan region east; southwestward in the Ft. Wingate region; and along the eastern part of the same state. On the plains are extensive outcroppings in southwestern Kansas, thence across Oklahoma into the northern and western parts of Texas. Vertebrate fossils of Triassic age have been reported from the Lander region (Williston, Branson), Como and Red Mt. (Reed and Williston) in Wyoming; from northeastern Utah (Lucas); western Colorado (Cross); northern New Mexico (Cope); Fort Wingate, New Mexico (Yale collections, Shufeldt); Pan Handle (Cope), and Claremont, Texas (Brown). The fossils, consisting chiefly of phytosaurs and labyrinthodonts, agree, for the most part, so closely with those of the Keuper of Europe that their horizon may be confidently fixed as Upper Trias. Below the horizon yielding Vol. XX, No. I I