4^ 



1869.] ^^ [Ilayden. 



Near the junction of Bitter creek and Green river there is a bed of 

 very singvil&r bitunainous earth which has excited much attention. It 

 has been used as a fuel and burned so readily in stoves, that some people 

 valued it more than true coal ; but it is not now much used. An analysis 

 shows that it is an inferior fuel.* The bed is usually about 4 feet thick, 

 but sometimes only 2 or 2^. It is often jsarted by several thin seams of 

 shale. These Green river shales or slates as they might be called, must 

 contain some calcareous matter, although not very fossiliferous. Possi- 

 bly a more careful study will reveal a greater variety of animal and vege- 

 table forms. 



In the same cuts between Green river and Bryan, a distance of about 

 13 miles, great quantities of fossil fishes occur in a kind of chalky slate. 

 Quite perfect impressions are formed upon the surfaces of the slates, 

 j)resenting the appearance of having been preserved in quiet waters. 

 Indeed all the Green river rocks may be said to possess a soft chalky 

 character. At Bryan some fine specimens of fish were obtained from a 

 well about 60 feet below the surface. 



On the distant hills of this locality are layers of a chalky limestone 

 which would make excellent lime and is now used as a building stone. 

 It has the appearance of oolite, and in fact is made up of an extinct unde- 

 termined species of Cypris. About 7 miles west of Bryan we have : 



4. Yellowish chalky laminated beds, very thinly divided. 



3. Thin layers of gray chalky limestone filled with fresh water shells 

 like Gorhula. 



2. Rusty indurated sandstone, somewhat shaly. 



1. Gray shale. 



Many of the layers in bed No. 3 are made up almost entirely of a small 

 , bivalve shell. 



About 2 miles above Green River Station the river cuts through a 

 great thickness of fine sand and gravel showing, on the slope and bottoms 

 a vast deposit of drift. Much of the shale in this region has a greenish 

 tinge, and the river in passing over them seems to have taken up some of 

 the green coloring matter, so that the water lias a peculiar green color 

 and hence the name. 



From Bryan to a point about 10 miles west of Fort Bridger the entire 

 surface of the country is covered with buttes of every shape, cones, 



* Mr. Carson's analysis of a specimen of this bituminous eartli gives the following constituents ; 

 Silicic acid, 18.58. 



Sulphuric acid, 3.88. 



Sesquioxlde of Alumina, 8.14. 

 Sesquioxide of Iron, 2.19. 



Lime, 14.11. 



Magnesia. 7.11. 



Carbonic acid, 17.40. 



Water, 2.90. 



Volatile Matter, 22.25. 



Fixed Carbon, 3.73. 



100.29. 



