MOOK, STUDY OF THE MORRISON FORMATION 47 



overlies the Lykins division of the Eed Bed series. The basal sandstone 

 varies from 10 to 20 feet in thickness. It is persistent and massive and 

 is used for building stone. It is somewhat calcareous. The lowest bed 

 of limestone varies in level, but may be within 15 feet of the basal sand- 

 stone. The intervening levels are composed of clay which is covered by 

 waste material. One bed of limestone 40 feet thick, according to Fenne- 

 man, occurs at South Boulder Canyon. At one locality there are three 

 distinct limestones separated by sandstones, the uppermost of the three 

 being about 30 feet thick. ISText follows 75 to 100 feet of covered beds, 

 probably soft clays. Limestones and clays interbedded follow this cov- 

 ered series, in turn followed by 15 feet or less of calcareous, iron-stained 

 sandstone. Above this sandstone the formation is composed of dense, 

 hard clays and argillaceous sandstones. 



MOEKISON" 



The deposits of the Morrison formation are not very well exposed at 

 the village of Morrison, six or seven miles west of Denver, from which 

 the formation takes its name. The beds outcrop on the western slope of 

 the hog-back at this local itv and are mostlv covered bv tahis from tlie 



Fig. 5. — The Murrivon juiniutiou at Morrison, Colorado, looking south 



