J. L. Rich — Stratigraphy of E, New Mexico. 295 



Art. XXL — The Stratigraphy of Eastern New Mexico — 

 a Correction; by John L. Rich. 



In a paper entitled ^^Contributions to the Stratigraphy 

 of Eastern New Mexico '' which appeared early in 1920,^ 

 there are certain statements and correlations which, 

 if allowed to pass unchallenged, are likely to lead to 

 much confusion. 



During the summer of 1919, the writer spent four 

 months studying the stratigraphy and structure of 

 Guadalupe and adjacent counties. A number of detailed 

 sections were measured, but, unfortunately, they are now 

 in the files of an oil company and are inaccessible, so that 

 only generalized descriptions of the sections can be 

 given here. 



The generalized section for Guadalupe and adjacent 

 counties is: 



Triassic. — Red and purple shales and sandstones 1500' =b 



Coarse gray sandstone, conglomeratic at base 



(Santa Rosa sandstone) 50-100' 



Triassic or Permian. — Brick red sandstone and red 



shale, becoming more shaly toward the base 150-200' 



Permian. — Red, brown and variegated shales and 

 sandstones with much gypsum, anhydrite, and 

 salt (Pecos Valley red beds of Baker and, proba- 

 bly, the Castile Gypsum of other writers). This 

 formation occurs in the form of a wedge, thinning 

 to the northwest, and thickening notably toward 



the southeast to 1000'± 



Blue-gray limestone with some gypsum (San An- 

 dreas limestone) (?) to 300'+ 



Sandstone, coarse, gray, massive (Glorieta sand- 

 stone) 300-500' 



Salmon pink sandstones and shales, with gypsum 



(Yeso formation) 700' ± 



Permian (or Pennsylvanian^). — Dark red sandstones 



and shales (Abo) 800' ± 



Baker has confused the Glorieta sandstone in parts 

 of the area with the Santa Rosa sandstone. This has 



^ Baker, C. L., this Journal (4), 49, pp. 99-126, 1920. 



^ Generally considered to be Permian, but thought by Bose to be Pennsyl- 

 vanian, at least in the lower part. See Bose, Emil, On Ammonoids from the 

 Abo Sandstone of New Mexico and the Age of the Beds which contain them, 

 this Journal (4), 49, pp. 51-60, 1920. 



