J. L. Rich — Stratigraphy of E. New Mexico. 29Y 



naturally led to the further confusion of the gypsiferous 

 series between the Santa Eosa and the San Andreas with 

 the Yeso. 



Speaking of the Yeso formation Baker says (pp. 

 110-111) : 



" .... and is exposed beneath Upper Trias in the anticlinal 

 axes along the Pecos River from Ribera southwards to beyond 

 Puerto de Luna and in Canon Blanco, a tributary entering the 

 Pecos a few miles below Anton Chico. It is also exposed for 

 many miles in upper Pintada Canon and forms the surface of a 

 large area west of Fort Sumner. Altogether it covers or proba- 

 bly underlies fully half of New Mexico east of the Rio Grande. ' ^ 



In this paragraph it is plain that he has confused 

 the gypsiferous series above the San Andreas with the 

 Yeso. It is the former, not the latter, which ''forms the 

 surface of a large area west of Fort Sumner. '' 



The gypsiferous series above the San Andreas wedges 

 out completely in western Guadalupe Co. where the for- 

 mations lap up over the buried granite mountain range 

 which has been revealed by drilling for oil in that region. 

 It appears a few miles to the southeast in Pintada Canyon. 

 From there toward the southeast it thickens notably. 

 The superficial resemblance of this formation to the 

 gypsiferous part of the Yeso is doubtless partly respon- 

 sible for Baker's miscorrelation. 



On page 112, Baker says : 



' ' The San Andreas is not known north of the line of the Belen 

 cut-off of the Santa Fe Railroad. ' ' 



As a matter of fact it is well exposed at Vaughn, north 

 of the railroad, from which it may be traced continuously 

 northward for 10 or 12 miles to the foot of the high mesa 

 visible from the railroad and it is at the surface in 

 several places on the plain between the mesa and Pastura. 

 It is also exposed on the Estaritos dome, already referred 

 to, and in the tributaries of Pintada Canyon north and 

 northeast of Encino. 



Speaking of the Upper Triassic rocks. Baker says, 

 p. 117 : 



"West of the Pecos River they extend at least as far south as 

 the Belen cut-off of the Santa Fe Railroad. ..." 



