TEIASSIC PLAXTS. 149 



nearly alwaj'S equally unfossiliferous. Its vivid color renders it a most 

 conspicuous feature in the geological structure of the region, enforcing the 

 attention of even the most casual observer. In thickness it ranges from 

 scarcely 100 feet in some localities to 1,500 or 2,000 in others. Wherever 

 exhibited it carries gypsum in greater or less quantity, and in the southwest 

 it holds notable amounts of salt. 



Near Abiquiu, N. Mex., and in Los Bronces, Sonora, the Red Beds 

 are found to contain beds of coal, and associated with them a large num- 

 ber of fossil plants. These have been described hj Dr. Newberry who 

 pronounces them similar to the plants from the Triassic coal basin of 

 Virginia and North Carolina and very like the Triassic plants of the 

 Old World, with which many of the genera and some of the species 

 appear to be identical. Fossil wood is also frequently found, and in Texas 

 and New Mexico it is very abundant. It is often saturated with sulphide 

 of copper, and in some regions this is found in such quantities as to have 

 been worked in former times by the Spaniards as an ore of copper. At a 

 locality in Southern Utah it is similarly saturated with silver ores. This 

 fossil wood, however, is of little paleontological value, and, with the excep- 

 tion of the plant leaves just mentioned and a few molluscan forms announced 

 within two or three years, the beds contain no proof of their age. 



With this dearth of fossils the greater part of the evidence for consid- 

 ering them of Triassic age is derived from their occupying a position 

 between unquestionable Carboniferous and Jurassic strata. In many 

 cases, however, the Carboniferous is unrepresented where the Red Bed 

 series occurs, and in a large part of its development in the Rocky Mount- 

 ains the overlying Jura is either undistinguishable or wanting. 



In Arizona near the Moqui villages Dr. Newberry found resting upon 

 variegated marls of the Triassic series, and immediately underneath Creta- 

 ceous sandstones, a stratum of lignite containing fossil plants closely allied 

 to Jurassic species of Europe.* 



In eastern Colorado the series, according to Dr. Stevenson, underlies 

 unconformably the Jura and Cretaceous,f and since along the eastern 



' Ives Colorado Report, pp. 79-8-2. 



I Survey West of the lOOtli Meridian, Vol. Ill, p. 379. 



