STRATIGRAPHY. 
11 
CLIMATE AND CULTURE. 
The climate of the region is arid, the mean annual rainfall at Grand 
Junction being only 7.8 inches. The vegetation, therefore, is of the 
desert type, and the shale lowland in its natural state is practically 
bare or yields a meager growth of desert plants. The uplands 
receive more rain and support stunted conifers, oaks, etc. In gen- 
eral, timber suitable for mining purposes is scarce. In the Grand 
Junction region timber for this purpose is imported, but in the western 
part of the field it is more plentiful. In the valleys where irrigation 
is practiced the desert has been converted into a garden, and por- 
tions of the area rival in productiveness any part of the country. 
The mean annual temperature is 53°, the summers being warm and 
the winters usually mild. The percentage of sunshine is 75 and gen- 
eral climatic conditions are delightful. In the irrigated areas con- 
tiguous to Grand, Green, and Price rivers there are a number of 
thriving settlements where fruit growing is an important industry. 
Grand Junction, the most important place in the field, is a typically 
progressive western town. The lowland is traversed in an east-west 
direction by the main line of the Denver and Rio Grande Railroad . 
DESCRIPTIVE GEOLOGY. 
STRATIGRAPHY. 
The general sequence of formations in the coal fields of the Uinta 
Basin, as determined by recent work of the United States Geological 
Survey." is shown in the following table: 
Geologic formations in Uinta Basin. 
Cretaceous. 
Jurassic 
System . 
Series. 
Formation. 
Tertiary. 
Eocene. 
Green River formation. 
Wasatch formation. 
Fort Union or older (?). 
Unconformity. 
i fpper Cretaceous. 
Unconformity. 
Mesaverde formation. 
Mancos shale. 
Dakota sands I one. 
To the subdivisions of the Cretaceous are given the names intro- 
duced bv Whitman Cross for southwestern Colorado/' This classi- 
aTaff, J. A., Pleasant Valley coal district, Utah, and Gale, Hoyi S., Coal deldsofthe Danforth Hills and 
Grand Hogback, Colorado: Bull. U. S. Geol. Survey No. 316, 1907. 
'•Cross, Whitman, La Plata folio (No. 60), Geologic Alias C. S., U. S. Geol. Survey, 1899. 
