146 KANSAS ACADEMY OF SCIENCE. 



phics. No remains of Cambrian, Silurian or Devonian strata are 

 recognized. If any of these systems were ever deposited, they appear 

 to have been completely removed, unless the metamorphics are rem- 

 nants. The upper surfaces of these Azoic masses are scored into 

 bosses and fosses, and the latter are filled with conglomerates and 

 quartzites on which limestones of the Carboniferous period lie con- 

 formably, the first clearly defined Paleozoic strata in the territory. 

 The whole series of the Carboniferous, except coal seams, is displayed, 



New Mexico appears to have been immersed in the sea when the 

 ferns and club-mosses of eastern Kansas formed dense cryptogamic 

 forests, for millions of years, flourishing upon hundreds of feet of the 

 dead bodies of their species. Most of the mountains have carried 

 upon their summits extensive and thick beds of Carboniferous lime- 

 stone, sometimes in nearly horizontal attitudes. On the summit of 

 the Sandia range, opposite Albuquerque, at an altitude of 10,000 feet, 

 are two vast tables of Carboniferous limestone several hundred feet 

 thick, lying one above the other and separated by a bed of sandstone. 

 Viewed from the city these beds appear horizontal, but in reality they 

 have a small dip to the east. They extend miles along the crest, and 

 their conspicuous light-colored and uniform borders present a strong 

 contrast to the darker, serried, granite pyramids that stud the steep 

 slope below. They attract the attention of the traveler as a remark- 

 able sight. No better illustration can be had of the slow, non- 

 impulsive elevation of granite ranges than the attitude of these 

 extensive tables 5000 feet above the base of their upheaved support. 

 The writer has seen masses of the debris of these strata composed al- 

 most wholly of small brachiopod shells loosely cemented by calcium 

 carbonate. Near to and opposite the escarpment sides of the moun- 

 tains the Carboniferous and other strata are usually canted up at high 

 angles. 



The Triassic and Jurassic are extensively displayed in northern 

 New Mexico, and probably in the southern part, west of the Pecos 

 valley, in all their colors. In various places the Jurassic is capped 

 with gysum fifty feet or more in thickness, which would represent 

 more than 25,000 feet of sea- water evaporated. The southern part of 

 the Gallinas and northern part of the Nacimiento mountains, about 

 eighty miles northwest of Santa Fe, have their summits covered for 

 many miles with gypsum, above Jurassic sandstones and shales, at a 

 height of 10,000 feet. Gypsum is found in various connections, but 

 most often with the Jurassic. West of the Sacramento mountains, in 

 the southeastern part of the territory, is an area of 600 miles cov- 

 ered with gypsum sands heaped into white dunes by the wind. It is 

 dangerous to attempt a penetration of this dazzling desert. In places 



