TRIASSIC. 517 



Basin have conveniently limited the use of this term to the lowest and largest member of the 

 series. The popular use of the term "red rock" is similarly restricted. 



The subdivision into "Lower" and "Upper" Wyoming, adopted for the Denver Basin, 

 would also be appropriate to the Boulder area. The lower division, however, clearly embraces 

 two Uthological units which it is desired to distinguish in this report. The lower and major 

 part consists chiefly of rather coarse arkose sandstones and conglomerates of reddish color, 

 while the upper and lesser part is a finer-grained quartzose sandstone of white, "creamy," 

 or Mght-reddish color. The coarse red sandstones were called the Fountain formation by 

 Cross in the Pikes Peak foho, a type section being crossed by Fountain Creek, near Manitou. 

 The summit of the Fountain formation is not exposed in the Pikes Peak quadrangle, but Darton " 

 has found the character of the Fountain, as described by Cross, to continue to a white sand- 

 stone corresponding with the "Creamy sandstone" of Eldridge, occurring in the Garden of 

 the Gods, to which the name Lyons sandstone is here given. 



No Triassic beds are known on the eastern slope from Canon City, Colo., south 

 to northern New Mexico, but in that region, northwest of Santa Fe, first Newberry 

 and later Cope found Triassic fossils in red beds. Cross ^®^ comments as follows:. 



While Marcou and other early explorers of New Mexico announced the presence there of 

 Triassic formations, the first fossUs indicating the correctness of this assertion were obtained 

 by Newberry in 1859. The fossils described by Newberry himself were fossil plants obtained 

 from the old copper mines near Abiquiu, a locahty on Chama River some 20 miles or less above 

 its junction with the Rio Grande. The plants are mainly cycads and conifers, and as they have 

 not been identified at many other localities they are of less importance to the present discussion 

 than the vertebrate remains described by Cope, to which reference will soon be made. 



The formation from which the Abiquiu plants were obtained is described by Newberry as 

 consisting mainly of red sandstones, with conglomerates and many variegated beds of soft 

 shales, with abundant saline efilorescences, which led him to characterize the red beds of New 

 Mexico and Arizona in general as the "Saliferous series." Fossil wood, often in tree trunks, is 

 mentioned. 



Although I can not find that Newberry mentioned vertebrate fossils in the Triassic beds of 

 the Chama Valley, it appears that he found some, for Cope, who followed him in the exploration 

 of the region, states that the first invertebrates from the Trias of the Rocky Mountains were 

 collected by Newberry with the Macomb expedition. Cope visited Chama Valley and the 

 Gallinas Mountains, lying west of it, in 1864, while on the Wheeler Survey, and obtained various 

 vertebrate fossils from the Triassic beds. 



The fragmentary remains described by Cope embrace teeth and bones of three dinosaurs, 

 two of which were generically determined as Lselaps and Palseoctonus. Similar portions of a 

 belodont crocodile were called Typoihorax coccinarium.. Associated with these were found five 

 species of Unio. 



This assemblage of forms suggests the fauna of the Dolores "saurian conglomerate." The 

 locahty is less than 100 miles southeast from the easternmost known exposures of the Dolores 

 formation, the intervening country being occupied by Cretaceous formations. It is therefore 

 very natural to suppose that the vertebrate and plant bearing Trias of Chama Valley may be the 

 direct equivalent of the lower Dolores formation. Apparently the fossiliferous strata of New 

 Mexico are not overlain by a massive red sandstone equivalent to the Wingate sandstone of 

 Dutton. The "Variegated marls" of Newberry, which seem clearly to belong to the McElmo 

 or Morrison beds, intervene between the "Sahferous series" and the Cretaceous. 



In regard to the Triassic portion of the Shinarump group of Powell in southern 

 Utah and northern Arizona, Cross ^" published the following statement : 



The Shinarump is the lowest of three formations or groups assigned by Powell to the Trias, 

 the others being the intermediate Vermilion Cliff sandstone and the White Chff sandstone at 



"Bull. Geol. Soc. America, vol. J5, 1904, p. 22. 



