U. S. GEOLOGICAL SURVEY BULLETIN 707 PLATE XI 
CASTLE ROCK. 
A well-known a. about 300 feet high, 33 miles south of Der It was tot noted and 
named by the Lo xpedition in 18 20. The cap rock, 60 or 70 feet thick, is made up of 
boulders of | vasion sus sizes cemented together (conglomerate) and stands aie Semen 
because it is harder than the underlying rock. Photograph by L. C. McClure, Denver. 
i 
, 
B. DOME ghee: PLATTE CANYON. 
— picture illustrates the manne — even the most massive granite may yield to the F 
ction of the we aaa It pee “sy off i ccessive curved layers much like the layers of an iq 
onion, leaving round or dome-shap aks ainies 3 of rock — x tee out in striking contrast to é 
ae" towers and pinnacles that generally occur on the walls of the canyon. Ph otograph by : 
ilway. : 
. McClure, Denver; furnished by the Colorado & Sonthern Ra 
