PERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. 

 Section II. POLEO CREEK Continued. 



Feet. 



Dark red and green clay 3 Lriwer Trias? Barron 



Coarse red and green sandstones 17 " 



Hard red sandstones, cliffs 3 " 



Red sandstone and clay with thin band of harder sandstone 18 " 



Hard, red, coarse sandstone 3 " 



Red clay 35 



Red sandstone, bluffs 23 Base (?) of Trias 



Red sandstone with thin seams of clay, reptile bones 18 Top (?) of Pennian 



Red clay with thin nodular layers 55 



Dark red, coarse sandstones (cliffs) 6 Permian, fossiliferous 



Red sandy clay 35 " 



Dark red, coarse sandstone, jointed 18 



Red clay, even texture, vertical rain erosion 50 " 



Dark red clay 8 " 



Red shaly clay 17 " 



Heavy gray sandstones 25 " 



Red sandstones and clays ? " 



About 1.5 miles beyond the little settlement called Capulin a stream flows 

 into Capulin Creek from the north along the line of a fault which divides the Mesa 

 Prieta from the Capulin Mesa. The strata of the Mesa Prieta at this point dip 

 slightly northwest, but those of the Capulin Mesa dip east and northeast. The 

 west face of the Capulin Mesa rises 1,000 feet or thereabouts above the valley of 

 the Gallina River. Just north of the Cerro Blanco is a high red wall similar to 

 that north of the Poleo Creek, the uppermost rocks bearing phytosaur remains. 

 It is confidently believed that the lowermost exposures here are of Permian age, 

 but no fossils were found. 



There is a sharp break between the Capulin Mesa and the Cerro Blanco. 

 The rocks of the latter dip sharply to the west and are overlain by the Jurassic 

 shales and the Cretaceous sandstones and shales. At the foot of these Upper 

 Triassic rocks, north of Cerro Blanco, and opposite the face of the Capulin Mesa 

 bluff before referred to, were found various small fresh-water invertebrates, and 

 bone fragments referred provisionally to the genus Coslophysis Cope. The horizon 

 of these remains can hardly be less than 100 feet above the basal Upper Trias 

 sandstones, and in all probability the original types came from the immediate 

 locality where the fragments were found by Case. The Cerro Blanco takes its 

 name from the massive beds of white gypsum which cap it, descending steeply 

 below the creek bed to the south and dipping to the west. From the top of 

 the Cerro Blanco one can look miles to the north and west, and the view there- 

 from is a revelation to the geologist. To the east lie the mesas of more or less 

 horizontal rocks of predominantly Upper Triassic age; to the west the strata are 

 deeply tilted and eroded into valleys; a few miles farther west the beds of the 

 Wasatch badlands lie horizontally upon the uptilted edges of the Mesozoic strata. 



Upon the whole, the general features of the Red Beds in northern New Mexico, 

 as in many places elsewhere, may be summarized as follows; 



The Upper Trias rocks, about 600 feet in thickness, perhaps more, are pre- 

 dominantly softer and lighter colored, often orange colored, yellowish, and whitish, 

 and more aeolian in character, with the upper or uppermost beds more or less 

 gypsiferous. These beds, as in the Lander region, have basal sandstones, reddish 

 or white, with conglomerate and clay layers below them yielding phytosaur and 

 labyrinthodont bones (both types were found at El Rito), corresponding well 

 with like vertebrates from the Keuper of Europe. Below these beds there are not 

 less than 350 feet (in the Lander and Kansas regions perhaps goo feet) of more 

 uniform red sandstones and clay layers, usually weathering into more vertical 

 blufifs. that are utterly barren of all fossils and supposed to be of Lower Triassic 



