MOOK, STUDY OF THE MORRISON FORMATION 



89 



east of Jelm, and in the Centennial Valley. Outcrops occur on both the 

 east and west sides of the Laramie Mountains. In the vicinity of Lander, 



the thickness of the formation is 235 



feet, consisting mainly of pale green 

 to maroon massive shales, with thin 

 beds of sandstone. Kear Fort Wash- 

 akie it i^ 200 feet thick, and has a 4- 

 foot sandstone bed near the middle. 

 The thickness in the Owl Creek re- 

 gion varies from 100 to 250 feet, in 

 general diminishing from east to 

 west. In this region the formation 

 consists principally of pale green 

 sandy shale, with some darker tints. 

 A thick bed of soft sandstone usually 

 occupies the central portion. "In ex- 

 tensive exposures on the east side of 



Fig. 48. — Section of the Morrison forma- 

 tion near Watson's ranch on Emiar road 

 just north of Oiol Greek, Wyoming. 



Scale, 125 feet to 1 inch. (Fisher.) 



Fig. 49. — Section of the Morrison and Sun- 

 dance formations in east Muff of North 

 Platte River, in sec. 9, T. 31 N., II. 11 W., 

 Wyoming. 



Scale, 125 feet to 1 inch. (Barnett.) 



Eed Creek, 3 miles east of the summit of Black Mountain, the formation 

 is about 150 feet thick." Darton gives the following section at this point : 



Feet 

 At the top, soft massive sandstones, mainly of buff color, also pink, lying 



on red and maroon olays 50 



Red sandy clays, with a few sandstone layers from 6 inches to a foot thick 50 

 Massive sandy clays of alternating bands of gray and maroon 50 



150 



The Morrison formation is well exposed in the vicinity of Medicine 

 Bow. In Como Bluff, a few miles east of this place, a good series of 

 outcrops occur, while on the opposite side of the anticline of which it 

 forms the southern limb, another series of outcrops are less well exposed. 



