MOOK, STUDY OF THE MORRISON FORMATION 



49 



by down-faulting and down-folding, has protected the Paleozoic and 

 Mesozoic sediments of the district so that they are bounded on the east, 

 north and west by the crystallines. 



A hog-back capjDed by the Lakota-Dakota sandstones extends northeast 

 from Canon City, and a similar hog-back extends northwest from a point 

 a few miles east of Canon City. The dips of these two hog-backs are 

 steep at their southern ends, but as they converge the dips become less 

 and change in direction. Instead of being toward the southeast and 



Fig. 7. — View northeast from Fremont Peak, near Canon City, Colorado. 



A indicates locality of the Marsh-Hatcher dinosaur quarry, B indicates the Morrison 

 outcrops in the hog-back near CaQon City. 



southwest respectively, the dip at the point where the Lakota-Dakota 

 capping of the two hog-backs becomes continuous is towards the south. A 

 short distance north of this point the dip lessens until the strata are nearly 

 horizontal. Oil Creek, a tributary of the Arkansas Eiver, cuts through 

 this flat area, exposing the underlying rocks in a series of cliffs. North 

 of this point a wider valley has been excavated, having the Triassic and 

 lower beds as a floor. This valley is known as Garden Park. 



The Morrison formation is exposed on the steeper eroded sides of the 

 hog-backs, in the narrow gorge of Oil Creek and its tributaries, and in the 



