THE PLAINS PROVINCE 



99 



"The rocks of the [Roswell] district comprise Hmestone, sandstone, clay, and 

 gypsum which are beHeved to be of Permian age. * * * The so-called Permian 

 series of this district consists of an upper red bed member of gypsum, red sand, 

 limestone, and clay 600 feet thick, forming the high bluffs along the east side of 

 Pecos River and underlying the recent deposits of Pecos Valley, and a lower 

 member of massive limestone, clay, and gypsum of undetermined thickness, which 

 constitutes high rugged slopes to the west. * * * 



"Permian (?) Series. 



"Red-bed division.— These rocks consist of alternating beds of gypsum, red 

 sand, and clay, with an occasional layer of dark-gray, compact limestone. The 

 gypsum predominates and usually occurs in beds about 10 feet thick. It is 

 often found, however, in thinner layers, interbedded with clay and limestone. 

 The red beds are provisionally placed in the Permian, although no fossils have 

 been found in them. * * * The upper part of the beds is well exposed in the 

 bluffs along the east side of Pecos River, where a number of sections have been 

 measured. * * *" 



A typical section of this bluff is as follows: 



East of Roswell: . ^^^*^- 



Alternating layers of gypsum and red sand, with an occasional layer of hmestone ... 50 



White gypsum ° 



Red sand ° 



White, thin-bedded gypsum 1° 



Red sandstone containing thin layers of limestone 24. 



White gypsum 5 



Red sand '-5 



Gypsum '° 



Red sand 3 



Gypsum 



Red sand ° 



Gypsum "+ 



Greenish-gray sandstone ^5 



Gypsum 



Total "7^ 



"Limestone diiision.— The massive limestone beds underlying the so-called 

 Permian red beds of this region consist mainly of gray, compact limestone, with 

 layers of soft sandstone, clay, and gypsum. In the upper part the limestone is 

 more or less thin-bedded and porous, and contains many sandy layers. * * * 

 Limestone outcrops along the west side of the district, and farther to the west 

 forms high, rugged plateaus, extending toward the mountains. Fossils are not 

 abundant in the formation, but in one locality northwest of Roswell a number were 

 collected, which consisted mainly of Schizodus and PlenropJiorus, preserved as casts. 

 According to Doctor Girty, the fauna and Hthology of these specimens suggest the 

 highest Carboniferous beds or the Permian of the Mississippi Valley in Texas." 



Beede^ has maintained that the red beds of the eastern side of the 

 Pecos Valley are equivalent to, or a continuation of, the upper red beds of 

 Texas and Oklahoma. He shows that the Capitan and Delaware limestones 

 shade north and east into red sandstones and shales, which he regards as a 



1 Beede, J. W., The Correlation of the Guadalupian and the Kansas Sections, Amer. Jour. 

 Sci., vol. XXX, p. 131, 1910. 



