Chapter XI. 



PERMIAN. 



Color, light gray. 

 Symbol, 11. 



Distribution: Southwestern United States; West Virginia, Ohio, and Pennsylvania; New 

 Brunswick and Nova Scotia. Elsewhere mapped with "Carboniferous undivided." (See 



fig. 13.) 

 Content: Permian limestone and red beds, Kansas to Texas; Permian red beds, New Mexico; 

 Opeche and Minnekahta formations, Black Hills; Dunkard group of the northern Appa- 

 lachians; red and gray sandstones and subjacent New Glasgow conglomerate of New 

 Brunswick, Nova Scotia, and Prince Edward Island. Includes some Triassic red beds in 

 mapping. 



Permian areas. 



Page. 



H-1 13-14 Texas and New Mexico 474 



I-J 12-13 Utah, Colorado, Arizona, and New Mexico (mapped in general with Triassic 



and Jurassic) 479 



I-J 14 Kansas and Oklahoma 486 



J-K 13 Southern Wyoming and northern Colorado (mapped with the Triassic and 



Jurassic) 490 



J-K 17 Pennsylvania, West Virginia, and Ohio 492 



K 10 Klamath Mountains, California (not mapped) 494 



K 12-13 Wyoming, northern Colorado,- and Utah (mapped in general with the Triassic 



and Jurassic) •- 494 



K-L13 Black Hills, South Dakota 495. 



K 15 Iowa 497 



L 20 New Brunswick, Nova Scotia, and Prince Edward Island 497 



H-I 13-14. TEXAS AND NEW MEXICO. 



The strata assigned to the Permian in trans-Pecos Texas and adjacent parts 

 of New Mexico comprise the Delaware Mountain formation, the Capitan lime- 

 stone, the overlying unnamed sandstones and limestones on the eastern flanks of 

 the Guadalupe Mountains, and the red beds of Pecos Valley, which include the 

 Castile gypsum and the Rustler dolomite. These formations outcrop in the areas 

 colored as Carboniferous undivided, and Richardson's descriptions of them are 

 given in Chapter VIII (p. 360). 



The Delaware Mountain formation and the Capitan Umestone contain a unique 

 fauna, named the Guadalupian, which has been described in detail by Girty,^"'^"^ 

 who tentatively assigned it to the Permian. (See p. 359, Chapter VIII.) 



The Capitan limestone, the uppermost formation known to contain the Guada- 

 lupian fauna, on the eastern flanks of the Guadalupe Mountains, southwest of Carls- 

 bad, N. Mex., is overlain by a few thousand feet of sandstone and limestone to 

 which formation names have not yet been given. These in turn are overlain by 

 the red beds of Pecos Valley, which, according to Richardson*"*^ — 



consist of a group of varicolored sandstone and shale, red predominating, interstratified with 

 beds of magnesian limestone and gypsum. In detailed study it is desirable to divide these rocks 



474 



