MOOK, STUDY OF THE MORRISON FORMATION 45 



tlier south in Colorado it rests upon the Fountain or Badito formations. 

 South of Beulah, in southern Colorado, the Morrison rests directly upon 

 the crystallines. In the canyon of Eio Cimarron, in Kew Mexico, it rests 

 on the Exeter sandstone. 



"The basal unconformity is one of widespread planation, with local 

 shallow channeling, but no perceptible discordance of dips" (Darton, 

 1904, 8). 



•The Morrison is present at intervals from the Platte River to Colorado 

 City. North of the gateway to the Garden of the Gods it is 130 feet 

 thick and rests upon a bed of gypsum. It is partly exposed at Colorado 

 City, where the beds are vertical. It is exposed again, after being cut oif 

 by faulting for a few miles south of Manitou, along the mountain front 

 to the vicinity of Canon City. It is also well exposed in this vicinity in 

 a structural basin north of Canon City. South of Caiion City the forma- 

 tion is not present for a considerable distance. It is present near Beulah, 

 where it rests on the gneisses. Forth of Beulah the "Dakota" is said to 

 rest directly upon the Fountain formation, showing the presence of an 

 erosion interval between the Red Beds, or possibly the Morrison, and the 

 "Dakota." The formation is exposed in the Greenhorn Mountains, where 

 it rests partly upon the red beds and partly upon the gneisses. The more 

 important areas of Morrison outcrops in the eastern region have been well 

 described in various reports, and summaries of these descriptions are 

 given below. 



The Morrison formation is overlain by the Lakota-Dakota series, the 

 lower beds of which are known in the southern Colorado area as the 

 Purgatoire formation. The contact is essentially conformable, but it is 

 sometimes extremely sharp, as north of Caiion City, and it is quite prob- 

 able that in many areas at least there is a stratigraphic break of slight 

 extent between the two formations. 



NOKTHERN" COLORADO 



The following sections are given by Darton of the Morrison formation 

 in northern Colorado (1904, 8) : 



Section northtoest of Laporte, Colorado 



Feet 



"Dakota," Coarse sandstone, with conglomerate at base 



Graj' massive shales, with thin limestone bed about 20 feet 



below top 80 



Morrison, Limestone, gray, with algae 6 



Sandy shale, reddish to buff, partly massive 20 



Pinkish and buff sandstone at top of Red Beds 60 



