CARBONIFEROUS UNDIVIDED. 363 



upper part is a bed of blue limestone 300 to 500 feet thick, with Pennsylvanian fossils, which 

 Lee has named the San Andreas limestone. Beneath this is the Yeso formation, consisting of 

 500 to 1,000 feet of yellow, pink, and white sandstones and shales, with gypsum and some 

 limestone. The basal formation of the Manzano group, to which the name Abo sandstone has 

 been given, is composed of dark-red sandstones interstratified with sandy shales. There are 

 distinct unconformities produced by erosion at the top and the bottom of the Manzano group. 



South of Socorro County Lee has traced the red beds of the Manzano group down to Rincon. 

 In the Franklin Mountains, according to G. B. Richardson, the Carboniferous "Red Beds" and 

 in fact all "Red Beds " are absent and the Pennsylvanian is represented by the Hueco limestone, 

 3,000 feet thick. Still farther east on the boundary line between Texas and New Mexico the 

 Hueco is covered by 2,500 feet of Guadalupian" sandstone and limestone. Near Silver City and 

 in the southwest corner of the Territory the Pennsylvanian consists almost exclusively of lime- 

 stones of moderate thickness. The "Red Beds" are absent and Cretaceous rocks carrying 

 Benton fossils rest with distinct unconformity on the eroded Carboniferous formations. 



In the Zuni Mountains, according to Dutton, there are 1,650 feet of Pennsylvanian and 

 Permian "Red Beds" resting directly on the pre-Cambrian rocks. In the Mora uplifts there 

 are, according to J. J. Stevenson, 3,276 feet of upper Carboniferous, consisting of sandstones, 

 shales, and limestones in rapid alternation. In the upper Pecos Valley, above Pecos, there is, 

 according to Lindgren, about 4,000 feet of the same series which apparently can not be further 

 divided. At neither place does this series comprise any "Red Beds." Several coal seams, at 

 least one of which is workable, are present. Between Pecos and Glorieta, the relations being 

 especially well exposed in La Cueva Creek, this lower series is covered by a thick mass of "Red 

 Beds" and coarse grits, containing some interbedded limestone, e^ddently of Paleozoic age. 

 These coarse grits are beyond doubt derived from the pre-Cambrian mass of Thompson and 

 Penacho peaks, just to the northwest, and their extensive development demonstrates the 

 existence of a land area along the Santa Fe Range and probably also an epoch of erosion within 

 Pennsylvanian time. Above these grits and "Red Beds" are similar strata of uncertain age 

 which underhe the Glorieta Mesa and which are capped by a yellow sandstone, outcropping at 

 the edge of the escarpment; the sandstone has been regarded as of Dakota age. The total 

 thickness of the "Red Beds" in the upper Pecos Valley, as measured by Newberry, is 1,350 feet. 



I 16. ALABAMA. 



Plant remains, probably of Carboniferous age, are recorded by Smith ^*^ from 

 the metamorphosed rocks near Moseley (now Erin), in Clay County, Ala., which 

 have been regarded as a part of the Ocoee group of Safford. (See Chapter III, 

 p. 90.) 



J 10. SIERRA NEVADA, CALIFORNIA. 



On pages 373-376 is given an account of the Carboniferous of northern Cahfornia. 

 South of the fortieth parallel in the Sierra Nevada occur schists, slates, quartzites, 

 and limestones, which constitute a metamorphic series not usually divisible and 

 which under the name Calaveras formation are assigned to the Carboniferous. In 

 the "Description of the gold belt" included in foUos of the Geologic Atlas of the 

 United States relating to the Sierra Nevada *^^ published prior to 1900 occurs the 

 following statement : 



The great mass of the Paleozoic sediments of the gold belt consists of quartzite, mica 

 schist, sandstone, and clay slate, with occasional limestone lenses. On the maps of the gold 

 belt these sediments are grouped under two formations : 



o Richardson, G. B., Paleozoic formations in trans-Pecos Texas: Am. Jour. Sci., 4th ser., vol. 25, June, 1908. 



