154 GEOLOGICAL SURVEY OF THE TERRITORIES. 



all cases of dikes tliese cleavage openings are lines of least resistance, and 

 form the apertures for tbe exit of melted material, and that the sur- 

 rounding strata are not disturbed only where the pressure from beneath 

 is too great. I would simply suggest, however, that it is quite probable 

 that as there are in nearly all rocks two sets of cleavage lines crossing 

 each other at certain angles, so there are two sets of gigantic cleavage 

 lines for the earth's surface, which have formed the lines of least resistance 

 to the elevation of the mountain ranges — the basaltic ranges in most 

 instances having a strike northeast and southwest, while the metamor- 

 phic ranges trend northwest and southeast. The eruption of the igneous 

 rocks is an event subsequent to the elevation of the metamorphic ranges. 

 Sometimes the eruptive rocks seem to trend northwest and southeast, or 

 nearly so. 



On the hills surrounding Trinidad are great quantities of impressions 

 of deciduous leaves in tlie rocks. The most conspicuous, as well as 

 abundant, fossil, is a species of fan palm, undoubtedly Sahal camphellii, 

 which occurs in the lignite beds on the Upper Missouri. This plant 

 would seem to have formed the dominant tree in ancient times, much like 

 the palmetto of South Carolina. In some places the calcareous sand- 

 stones are filled with this plant for miles. There are also, in considerable 

 abundance, leaves of the Jfa^fJioZm, Platanus, Laurus,&c., and, so far as I 

 can determine, identical with the species found on the Upper Missouri. I 

 do not doubt for a moment that all the coal beds of the Eaton Mountains 

 are tertiary and belong to the great coal system which has already been 

 traced over such a wide area. In a little dry creek I observed an out- 

 crop of coal, about two feet thick, with drab clay above, filled with brown 

 iron ore, and above this a gray laminated sandstone. In this sandstone 

 a huge specimen of the Sabal was found. 



About four or five miles up the Purgatory Eiver, above Trinidad, on 

 the south side of the creek, I examined two openings that have been 

 made for coal. It is the same bed in both i)laces, and is aboutfour orfive 

 feet thick at the outcrop. Underneath it, is a sort of indurated sandstone 

 with very irregular laminae, with thin layers of vegetable matter. 

 Immediately beneath the coal is four to six feet of drab arenaceous clay, 

 with large concretionary masses of iron ore of excellent quality; above 

 ,the coal is drab clay passing up into sandstone. These openings for 

 coal are about fifteen feet above the bed of the creek, and the strata are 

 nearly horizontal. The clay above the coal at the other opening, not 

 far away, is, perhaps, eight feet thick, and full of iron ore, with leaves 

 like willow and nuts and small filiform leaves like grass. The clay is 

 a drab steel color passing gradually up into a very rugged sandstone with 

 projecting hard layers, which give a wall-like appearance to the bluif-like 

 sides. Fr^m the Spanish Peaks to Trinidad, and along the Purgatory- 

 Creek for four miles above, the black shales of the cretaceous are visi- 

 ble. Usually in this region these drab shales pass into a series of 

 alternate clays and sandstones in thin layers, and upon them rests a 

 conspicous bed of rusty yellow sandstone, which I have regarded as the 

 lowest bed of the tertiary series. A bed of sandstone precisely similar to 

 this, and holding the same geological position, occurs at CaQon City and 

 the Laramie Plains. But at these localities the intermediate cretaceous 

 beds, Nos. 3, 4, and 5, are not absent, while in the Raton Mountains the 

 sandstone seems to rest directly upon the lower cretaceous formation, 

 Xo. 2. I have searched this sandstone over an area of many miles for 

 fossils, and I only succeeded in finding one obscure fragment of a marine 

 bivalve like the clam, while in the mud beds and shales below, speci- 

 mens of Inoceramus are common. I make this sandstone, therefore, the 



