GEOLOGICAL SURVEY OF THE TERRITORIES. , 321 



sea in which tbey appear to have lived ; for their stems i^enetrate 

 the saudstone in every direction. And this indication is still more 

 manifest in the great abundance of debris of land-plants which seem as 

 ground by the waves, thrown upon the shore and mixed in the sand 

 with fucoidal remains. This slow upheaval, and its result in the forma- 

 tion of a new land, are read as in a book in the fossil remains of this 

 group of sandstone, and every observer should forcibly admit that these 

 memorials of old expose the beginning of a new era, or of what we call 

 a new formation. This conclusion, however, can be warranted only if 

 by further researches we recognize that this fucoidal sandstone is not 

 a mere local formation ; that it covers a wide area, preserves everywhere 

 its relative position to the Cretaceous under it, and to the lignitic beds 

 above, and has always the same characters either in its compounds or 

 in its fossil remains. 



That this sandstone forms all over and around the Raton Mountains 

 the base of what is called the Lignitic formation, and that it there over- 

 lies the black shale No. 4, has been remarked by all the geologists who 

 have explored the country. Dr. F. Y. Hayden describes it briefly but 

 very exactly in his section* as ^^ a m-assive, heavy-hedcled sandstone, yel- 

 loicish gray, for icMtish,) rather concretionary in structure, and weathering 

 hy exfoliation, over Cretaceous shales with Inoceramus and Ostrea,^^ this 

 last bed remarked elsewhere as Cretaceous No. 4, Nothing is said of 

 the characters of its remains. But the specimens of fossil-plants gath- 

 ered at the Eaton Mountains by Dr. Hayden and his party, some of 

 them marked : from the sandstone below the coal, bear fucoidal plants, 

 representing the species of Halymenites, yf^hich, by the abundance of its 

 remains, appears essentially characteristic of the marine flora of that 

 period. Dr. Hayden still remarks it toward the southern end of the 

 Eaton Pass, where the Lignitic formation, 100 to 150 feet thick, containing 

 two or three small seams of coal, rests immediately upon an irregular 

 bed of alternate thin layers of mud, sandstone, and clay, which he calls 

 beds of passage between the Cretaceous and the Tertiary of that region. 

 Dr. John Leconte, considering the same strata as Cretaceous, mentions 

 them in his report f as continuing south v/ard of the Eaton along the 

 base of the Eocky Mountains, '^forming like an immense terrace, which 

 exten/Js as far south as the valley of the Tonejo, and perhaps even to the 

 north hank of the Gim.arronP They are evidently the same sandstone- 

 beds as those of the Eaton Mountains; for the same geologist remarks 

 that they were observed by him northward from Trinidad and far toward 

 the Arkansas. Indeed, from this j)lace northward to the base of the 

 Spanish Peak, these sandstone-beds, always with the same characters 

 and the same thickness as marked for the eight first members of my 

 second section, 207 feet, and always immediately over the Cretaceous 

 No. 4, form like an immense terrace perpendicularly, cut like a wall 

 facing east, high above the ijlain. They support the lignitic beds which, 

 still tower above them, either ascending in steep declivities from the 

 top of the perpendicular sandstone, or receding at some distance where 

 they have been more deeply sapped by erosion. " This abrupt front^^ 

 says Dr. Hayden, '•'•seems to form a sort of shore-line of a wonderful basin, 

 as if a body of water had swept along and washed against the high bluffs, 

 as along some large river.'''' | The stage-road from Trinidad to Pueblo 

 follows the base of the cliffs for thirty-two miles; and, from each station, 

 a geologist has convenient opportunity for the exploratiion of these re- 



*Report 1869, page 57. 



t Notes on Geology, &c., loc. cit., pp. 22 and 23. 

 X Dr. F. V. Hayden's Report, 1869, p. 53. 

 21 G s 



