•« PALEONTOLOGY OF NEW- YORK. 



the Gulf of Mexico, belong to the same limestones which in the Coal mea- 

 sures of Ohio and other Western States, appear in bands of a few feet in 

 thickness. 



From the Report of Captain St.\nsbcry*, we learn that extensive moun- 

 tains, or even ranges of mountains, in the neighborhood of the Great Salt 

 Lake are composed of this Upper Carboniferous limestone. Some of these 

 mountains have an elevation of three thousand feet above the plain ; and, 

 though quite unaltered in their condition, rest upon metamorphic strata, 

 similar in character to those of the Appalachian range. This limestone has 

 been identified by its fossils in the neighborhood of Fort Laramie : it is 

 known from observations along the line of the United States and Mexico 

 Boundary Survey ; it is also known from collections made near Santa Fe, 

 New-Mexico, at the Pecos village, the MogoUon mountains, at El Paso on 

 the River San Pedro, in the Gaudaloupe mountains, and many other locali- 

 ties. From the massiveness and compact texture of some specimens, and the 

 subcrystalline character of others, we are prepared to learn that this rock 

 has become extensively developed in that region. The shaly beds which 

 accompany this limestone in its more northern and eastern localities, and 

 are there often more conspicuous than the limestone itself, have so far 

 diminished that they form no marked feature in the topography; nor 

 has this character been shown in any of the sections of strata which I 

 have seen from that region. 



It is either at the base of this formation, or associated with the lime- 

 stone itself, that we are to look for productive Coal measures ; but up to 

 this time, we have no positive information that coal has been found in this 

 association in the northwestf . Farther to the southwest, the occurrence of 

 coal has been mentioned by several explorers of that region. Several spe- 

 cimens of coal accompanied the collections made by the naturalists of the 

 United States and Mexican Boundary Survey, but these were not accom- 



* SrxMnvMX, Expedition to the Great Salt Lalce, 1852. 



t The collcctiona made by Captain Staksburt, in his Kxpedition to tlie Salt Lake, contain some slaty 

 coal and shale; and the occurrence of Sigillaria and Calamilet is mentioned in the journal of the natu- 

 ralist accompanying the expedition. No fossils of this character were preserved in the collections, and there 

 way still remain some question in regard to this matter, until wo have farther inrormatlon. 



