in West Texas and Southeast New Mexico. 333 



At the base of the Manzano Range the extreme western part 

 of the plateau is underlaid by several feet of limestone 

 (Magdalena ?) containing a Pennsylvanian fauna, allied to that 

 of the Hueco formation, and above the limestone there is a great 

 mass of red beds that outcrop as far as the vicinity of Lucy, a 

 railroad station about 45 miles east of the Manzano Range. The 

 rocks consist of prevailing fine-textured dark red sandstone 

 with which are associated layers of red sandy shale and lenses 

 of gypsum ; and thin beds of limestone, containing numerous 

 Pennsylvanian fossils, also occur towards the upper part of the 

 section. 



Five miles south of the town of Willard, at the crossing of 

 the Santa Fe Central Railway, 25 miles east of the Manzano 

 Range, the following section was measured : 



Section Five Miles South of Willard, New Mexico. 



Feet. 



Limestone, grey, cherty, fossiliferous 50 



Sandstone, grey, friable 300 



Sandstone, red 10 



Gypsum, massive, bluish white 100 



The fossils in the limestone are of Pennsylvanian age, so that 

 the great mass of red beds lying between limestones contain- 

 ing Pennsylvanian fossils clearly are of that age. These beds 

 belong to the Manzano group, but on account of the varied 

 stratigraphy it cannot at present be stated that the limestone 

 at the top of this local section is the San Andreas limestone, or 

 one of several other lenses in the Manzano group. 



The eastward continuation of the red beds is interrupted at 

 the divide between Estancia and Encino valleys by an area of 

 low relief, about ten miles wide, that is underlain by a crystal- 

 line complex consisting of granite and other igneous rocks, 

 slate, etc., which apparently represent the southward continua- 

 tion of the pre-Cambrian core of the Pocky Mountains. About 

 fifteen miles southeast of this area, northeast of Torrance on 

 the El Paso and Southwestern Pailroad, isolated areas of mica 

 schist surrounded by unconsolidated deposits were also found. 

 The relations of these ancient rocks to the red beds is obscured 

 by Quaternary material and is not known. 



East of this crystalline area the character of the underlying 

 rocks is much obscured by surface debris, but the general low 

 eastward dip apparently prevails throughout the region. Lion 

 Summit, just east of Encino Yalley, is formed by about 50 feet 

 of white sandstone capped by a bed of limestone in which no 

 fossils were found. Thence eastward down the long, gentle 

 slope of 60 miles to Pecos River there are few exposures of 



