334 Richardson — Stratigraphy of the tipper Carboniferous 



bed rock. The surface is general] y covered by Quaternary 

 debris, but a number of exposures show the presence of red beds 

 and gypsum dipping low to the east, and records of deep wells 

 indicate that al] of this area is underlain by red beds. For 

 instance, a well at Yaughan, a station at the crossing of the El 

 Paso and Southwestern Railway near the western end of this 

 long slope, is 1,355 feet deep in red beds all the way ; and 

 a well at Ricordo, 62 miles southeast of Yaughan along the 

 railroad and thirteen miles west of Pecos River, shows red 

 beds, below a superficial coating of sand, down to a depth of 

 595 feet. It appears then that red beds dipping eastward at a 

 low angle underlie the entire area between Yaughan and Pecos 

 River, and assuming a dip of only one degree a thickness of 

 approximately 6,000 feet of strata is thus indicated. Practi- 

 cally the entire plateau, therefore, between the Manzano 

 Range and Pecos River, with the exception of a small area 

 of ancient crystalline rocks, is underlain by gently east dipping 

 red beds which, unless they are duplicated by faulting, of 

 which no evidence has been obtained, are more than 9,000 

 feet thick. 



No fossils, excepting fragments of wood, have been found in 

 the red beds between Willard and Pecos River. A thin section 

 of a fragment of wood from the red beds one mile east of Pecos 

 River, 65 miles north of Roswell, New Mexico, was reported 

 on by David White as follows : This fragment " has lost many 

 of its trachial punctations by reason of advanced bacterial 

 action which has also obliterated many of the medullary rays. 

 On the basis of the remaining ray features and the occasional 

 obscure pores, I am disposed to regard this specimen as post- 

 Pennsylvanian. These rocks are the northern continuation of 

 the red beds of Pecos Yalley described above, and here also 

 they are unconformably overlain by the Dockum formation 

 (Triassic), which in turn is succeeded by the Tertiary deposits 

 of the Staked Plains. 



The point to be emphasized about this section between the 

 Manzano Range and Pecos Yalley is that almost the entire 

 history of upper Carboniferous sedimentation is a record of 

 red bed deposition, which is in marked contrast with the cor- 

 responding record in southern New Mexico and Texas. 



Section^ across southeast New Mexico between Tularosa 

 Desert and the Staked Plains (No. 3, figs. 1 and 2).— The 

 section in the Sacramento and Guadalupe Mountains in south- 

 east New Mexico exposes a great thickness of rocks and reveals 

 the stratigraphic position of the strata which contain Girty's 

 Guadalupian fauna, the correlation of which has caused dis- 

 pute. 



East of Tularosa Desert, the local name of the bolson plain 



