80 



GUIDEBOOK OF THE WESTERN UNITED STATES. 



Xjt^notreo 



3AIJQ 3Ul|A>(g< 



uoneuujoj uosijjo[^ '/ 



:aXBp3^JBjj( 





as 



II 



•?! &^ 



at different elevations before the 

 granite was arched and broken by 

 faults, as shown in figure 16. Thus 

 the lowermost formation at Canon 

 City may have originally extended 

 onto the granite a mile or so and the 

 next one 2 or 3 miles, and so on, until 

 finally, when the Morrison was de- 

 posited, the entire area was low, and 

 the Morrison beds were laid down 

 continuously from Canon City to 

 Parkdale. 



West of milepost 170 the beds dip 

 sharply toward the west, as shown in 

 figure 16, and the Dakota disappears 

 under the dark shale of the Benton. 

 About 1,500 feet beyond milepost 170 

 the shale is in contact with the gran- 

 ite, which shows that they must have 

 been brought into this abnormal re- 

 lation by a fault that dropped the 

 shale on the east as compared with 

 the granite on the west. This rela- 

 tion of the shale and the granite is 

 illustrated in figure 16. 



Beyond this fault the hill on the 

 north (right) of the railroad is com- 

 posed entirely of granite, but on the 

 south the variegated shale of the 

 Morrison rests on the granite just as 

 it was deposited ages ago. At the 

 point where the railroad crosses Tal- 

 lahassee Creek the Morrison outcrop 

 swings to the north, and a hill com- 

 posed of this formation, capped by 

 Dakota sandstone, which dips toward 

 the west, may be seen half a mile 

 away. The sedimentary rocks can 

 not continue in this direction much 

 farther, for the granite, which can be 

 seen on the north, makes a high rim 

 completely around the valley. 



The rock in the middle of the val- 

 ley is concealed by a deep cover 

 of gravel, which the river has evi- 

 dently brought down from the high 



