30 EXPLORING EXPEDITION FROM SANTA F 



ENCHANTED SPUING TO COTTONWOOD SPRING. 



TERTIARY AND LOWER CRETACEOUS STRATA. 



At Enchanted Spring the Lower Cretaceous sandstones form a line of bold Mull's, 

 which border the excavated valley of the Cimarron. From this point up to the base 

 of the mountains the surface has nothing of the monotony of the plains below, but is 

 greatly varied, and the scenery is frequently impressive, occasionally grand. With 

 the exception, however, of the volcanic outlayers of the Raton Mountains, there arc- 

 few evidences of the action of violent disturbing causes, and the variety which the 

 scenery presents is due almost entirely to the erosion of nearly horizontal strata by the 

 drainage from the Rocky Mountains. Here the traveler, journeying to New Mexico, 

 obtains his first view of the peculiar and impressive scenery so characteristic of nearly 

 all portions of the great central plateau of the continent. Here he first hears the word 

 mesa, and sees it embodied in the long lines of table-lands which fill the horizon and 

 stretch away in perspective, like the walls of Cyclopean cities. I have, in a former 

 report, described somewhat in detail the phenomena of erosion which are presented by 

 the high table-land bordering the Rocky Mountains. It is, therefore, only necessary 

 for me to say in this connection that the views then advanced in reference to the origin 

 of the great natural features of that region, its mesas and canons, have been fully con- 

 firmed by subsequent observation, and that there can be no question that they are to 

 be regarded simply as phenomena of surface erosion, of which they are the grandest 

 examples known. 



The geology of the region lying between Enchanted Spring and Cottonwood 

 Spring is similar throughout. The rocky basis of the country is formed by the Lower 

 Cretaceous sandstone, covered here and there with patches of white tufaceous Tertiary 

 limestone. These Tertiary beds were, perhaps, once continuous, but now form only a 

 relatively thin covering over the divides between the streams, being wholly removed 

 from the valleys and lowlands. As on the Arkansas, they an; without fossils as far as 

 ol (served, and were deposited nearly horizontally over the irregular surface of the 

 underlying sandstone. 



A section of the strata at Cedar Spring is as follows: 



(.) Tertiary. 



1. White, chalky, tufaceous limestone, with hard, gray, compact bands If) feet. 



2. Cream-colored, spongy, tufaceous limestone, (similar to that on the Arkan- 



sas and Cimarron) 40 feet. 



(/>.) Cretaceous. 



1. Yellow fine-grained sandstone, with obscure impressions of fucoids G feet. 



2. Light blue or white shale, \\*ith many obscure vegetable impressions, about 4 feet. 



3. Yellow sandstone, soft and rather coarse, in thin (often rippled-marked) 



layers, containing impressions of dicotyledonous leaves, resembling those 



of Salix and Quercus 5 feet. 



