coal. 323 



List of mines in the Denver Basin, including worked and abandoned — Continued. 



1 Some of the mines noticed as worked may be at present temporari y closed. 

 GEOLOGICAL OCCURRENCE OF THE COAL. 



With the exception of the coal on the eastern border of the basin, in 



the vicinity of Scranton and Coal ('reek, which is upper Laramie, the 

 workable beds of the several fields about Denver are confined to the series 

 of sandstones and shales that constitute the lower 200 feet of the formation. 

 They probably attain their maximum depth of about 2,300 feet on the 

 line of Section V, shallowing north and south of this. They are sharply 

 upturned along their western border; along the northwestern, dipping 

 gently to the southeast; while beneath the prairies they are probably 

 thrown into a great number of minor folds and faults. The transverse 

 sections of the held show the general configuration of the coal horizon to 

 be that of an unsymmetrical shallow basin, the western and northern limits 

 clearly defined, the southern and eastern indefinite. 



The coal beds of the Denver Basin occur under three different 

 conditions: (a) That in which the beds belong to the lower division of the 

 Laramie and are steeply inclined along the foothills of the Colorado range; 

 (6) that in which the beds are also of the lower Laramie but occupy an 

 approximately horizontal position beneath the prairie; and (c) that in which 



