THE BASIN PROVINCE 141 



On Ilthologic grounds, however, it is thought that rocks of more than one age 

 are present." 



Knopfs suggests the name Onwenyo limestone for a small mass of lime- 

 stone appearing on the slopes of the Inyo Range facing Owens Valley, which 

 he considers as perhaps equivalent to the "Upper Coal Measure limestone" 

 of Hague's Eureka report. This formation "consists in the main of massive, 

 grayish, crystalline to compact limestones. The 2-foot basal bed is a blue- 

 gray compact limestone fossiliferous from the contact and carrying irregular 

 lenses and stringers of sandstone whose grains are apparently derived from 

 the Reward below. Here and there through the Onwenyo, particularly in 

 its upper third, are layers carrying rounded chert pebbles. The higher 

 beds are fairly massive and break down in large blocks on weathering. The 

 limestones as a whole are bluish gray to dark in color, compact to crystalline 

 in texture, and carry abundant fossil remains." The fossils suggest the 

 Spiriferina pulchra fauna, which is "more or less characteristic of the 

 Phosphoria formation of Idaho, the Park City formation of Utah, and 

 the Embar formation of Wyoming." (Girty in Knopf's paper, page 44.) 

 Girty's advice is: "You had best refer your collection to the Permian and 

 correlate it with the Park City, Phosphoria, and Embar, though the Park 

 City contains some Pennsylvanian and the Embar contains Pennsylvanian, 

 Permian, and Triassic." 



This connects the upper Paleozoic of the west coast of the United States 

 with the Cache Creek series of the international boundary and probably 

 through that series with the northern deposits of Montana, Idaho, and 

 thence south. 



B. PERMO-CARBONIFEROUS OF NEW MEXICO. 



The southernmost extension of the Permo-Carboniferous beds of the 

 Basin Province is exposed in the Rio Grande Valley. As far south as 

 Alamogordo red beds occur which can be traced through the State north 

 nearly to the north line. These have been included in the Manzano group, 

 which in general includes the 



San Andreas limestone. 

 Yeso formation. 

 Abo sandstone. 



These deposits were described by Lee and Girty^ in 1909. The Abo is the 

 lowest. 



(Page 12.) "It consists of coarse-grained sandstone, dark red to purple in 

 color and usually conglomeratic at the base, with a subordinate amount of shale, 



^ Knopf, Adolph, A Geological Reconnaissance of the Inyo Range and the Eastern Slope of 

 the Southern Sierra Nevada, California, Professional Paper No. no, U. S. Geological 

 Survey, 1918. 



^ Lee, W. T., and G. H. Girty, The Manzano Group of the Rio Grande Valley, U. S. Geo- 

 logical Survey, Bull. 389, 1909. 



