GEOLOGICAL SURVEY OF THE TERRITORIES. 99 



Green River, a soft synclinal basin, the marine Tertiary dipping west 

 about 10° on the east side, and the same marine beds inclining- east 3° 

 to 6° on the west side, while at Table Rock, Red Desert, and Washakie 

 there is a large thickness of purely fresh-water shells, of the generse Pa- 

 ludina, Unio, Melania^ &c. Table Rock is a square butte, rising up above 

 the level of the road about 400 feet. This is composed of beds of sand- 

 stone, which, in many instances, is little more than an aggregate of 

 fresh-water shells. 



After leaving Bitter Creek Station, the hills approach nearer the road 

 and show the character of the marine Tertiary again. 



Seams of coal appear in many places, while yellow arenaceous marls, 

 light-gray sand with indurated clay beds, and more or less thick layers 

 of sandstone, occur. The dip of the beds varies from 3^ to 6° east or 

 nearly east. 



At Black Butte Station on Bitter Creek, and 15 miles west of Bitter 

 Creek Station, there is a bed of yellow sandstone, irregular in thickness 

 and in part concretionary. It is full of rusty concretions of sandstone 

 of every size from an inch to several feet in diameter. They are mostly 

 spherical in shape, and when broken open reveal a large cavity filled 

 with yellow clay or dust of oxide of iron. 



This sandstone is 150 to 200 feet in thickness, forms nearly vertical 

 bluffs, and is now, by the action of atmospheric influences, worn into 

 the most fantastic shapes. Above this are sands, clays, sandstones of 

 every texture, coal-beds, &c. One of these coal-beds near the summit 

 of the hill has been burned, baking and melting the superincumbent 

 beds. 



I found in several layers the greatest abundance of deciduous leaves, 

 and among them a palm-leaf, probably the same species which occurs in 

 the coal-beds on the Upper Missouri, and named Sabal campbelli. There 

 is a seam near one of the coal-beds made up of a small species of Ostrea. 

 The railroad passes down the Bitter Creek Valley, which has worn 

 through the Tertiary beds, and on the east side the high walls can be 

 seen inclining at small angles. As we pass down the valley toward Green 

 River, the inclination brings to view lower and lower beds. These are 

 all plainly marine Tertiaries, while an abundance of impressions of plants 

 are found everywhere j no strictly fresh- water shells occur, but seams of 

 Ostrea of various " species. There are also extensive beds of hard, flat 

 table-rocks, which would make the best of flagging-stones. On the sur- 

 face are most excellent illustrations of wave-ripple marks, and at one 

 locality what appears to be tracks of a most singular character. One of 

 the tracks appears to have been made by a soliped, and closely resembles 

 the tracks of mules in the soft ground on the river-bottom. Others seem 

 to belong to a huge bird ; another to a four-toed pachydermatous ani- 

 mal. I have obtained careful drawings of these tracks, as well as speci- 

 mens of them. 



In the final report some detailed sections of these Tertiary beds will 

 be given ; yet I am convinced that local sections are not important. 

 The character of the beds is so changeable that two sections taken ten 

 miles apart would not be identical, and, in some cases, not very similar. 

 The more recent the age of formation the less persistent seems to 

 be their lithological character over extended areas. Although the coal- 

 beds seem to be abundant everywhere along the line of the road, in 

 the Lower Tertiary deposits, yet they have been wrought in few locali- 

 ties as yet. 



Near Point of Rocks Station, about 45 miles east of Green River, one 

 of the best coal mines I have yet seen in the West has been opened. Mr. 



