GEOLOGICAL SURVEY OF THE TEREITOHIES. 331 



springs come out from its base, it is continuous to Carbon in repeated 

 and deeper undulations, forming basins, which at this place and around, 

 contain the upper Lignitic formation with remarkably thick beds of 

 combustible mineral. The coal is mined at Carbon Station by a shaft 

 descending through the following strata : 



* Feet. 



1. Shale, clay, and sandstone, at top , 35 



2. Ferruginous shale, with dicotyledonous leaves ;i 



3. Clay, shale, and sandstone, with the plants at top 18 



4. Coal, (main) ., 9 



5. Fii-e-clay and shale, with dicotyledonous plants 20 



6. Coal 4 



7. Fire-clay and shale 8 



8. Coal ..J 4 



101 



In following the railroad to about one mile west of Carbon, the upper 

 coal is seen exposed in a cut, under a thick layer of compact, gritty 

 sandstone, resembling the millstone-grit or the Mahoning sandstone of 

 the Carboniferous formations, not only by its composition, but by the 

 quantity of pieces of wood or streaks of coal mixed with it at its base. 

 The wood is either petrified (not silicified) or transformed into coal, 

 forming irregular thin layers which j)as8 into the sandstone in various 

 directions, sometimes ascending nearly vertically one or two feet high, 

 and abrui^tly disappearing. This bank, too, has in some irregular small 

 cavities pebbles of sandstone ; even fragments of rolled wood trans- 

 formed into coal, indicating its formation as that of a beach where the 

 waves brought with the sand and imbedded into it materials of various 

 kinds. Above this sandstone are beds of fire-clay with silicified wood, 

 overlaid by thick layers of sandy shale, with fossil-leaves of dicotyle- 

 donous species, the whole topped by another thick stratum of coarse 

 conglomerate sandstone. In the rubbish along the railroad I found one 

 specimen of fucoid. I should have liked to examine the country with 

 more details, especially in order to compare the distribution and the 

 composition of this upper conglomerate sandstone with that of the upper 

 member of the Lignitic of Colorado, and thus to possibly recognize an 

 analogy of formation. But my attention was claimed by the examina- 

 tion of fossil-plants found at Carbon in great quantity, and my whole 

 time had to be gvein to their study. These plants are obtained from 

 two horizons : No. 2 and Xo. 5 of the section, separated by 35 to 40 feet 

 of measures. 



§ G. Caebon to Black Butte Station. 



From Carbon westward the country and its geological characters and 

 modifications have been, too, so exactly and minutelj^ described by Dr. 

 Hayden in the same report of 1870, pp. 134 to 140, that, besides mj 

 paleontological researches, I had, in following the railroad to Evanston, 

 little else to do but to record by comparison the exactness of the geo- 

 logical facts and descriptions already x>ublished. It was the case at 

 Eawling's Station, the first place where I stopped, after passing Carbon, 

 to examine what had been indicated to me by Mr. William Cleburn, civil 

 engineer of the railroad, as " peculiar rocks, containing an immense 

 quantity of fucoids," which, from descrii)tion, I supposed might indicate 



* For the communication of this section and other valuable information, my thanks 

 are given to Mr...J. Williams, the able supp.riuteudeut of the Carbon mines. 



