+ + + + 



+ 4--' + + + 



152 W. O. CROSBY — ARCHEAN-CAMRRIAN CONTACT IN COLORADO 



entirely and the other nearl}^ enclosed by the sandstone, and probably 

 indicating complex oblique faulting before the consolidation of the sand- 

 stone, the enclosed sand form- 

 ing now, virtually, a sandstone 

 dike. Farther on the contact 

 drops irregularly about 4 feet 

 (figure 25). This is probably 

 not a fault, l)ut one of the most 

 marked of the original irregu- 

 larities of the granite surface. 

 The spheroidal structure is ad- 

 mirably developed in this part 

 of the granite. Continuing to- 

 ward the north end of the out- 

 lier, we have first two faults (figures 27 and 28), and near the reversed 

 fault the sandstone is well slickensided. Then comes an original in- 

 N. S. 



Figure 23. — Contact broken by a Gravity Fault. 



■^ + ^ 



I inch = lOfeet. 

 I-'iGUKK 2i. —Probable obliijiic Faidtiiifi aiid Sliearhu/ of tlir Contact. 



equality due, apparent!}', to the wearing or weathering out of one of the 

 spheroidal masses of granite (figure 26). A general view of this west 



E. • W N. S. 



+ + +,+ + +,+ 



+ 



I inch = 5" -feet. 



Figure 25. — Small Erosion Scarp of the 

 Granite Surface. 





I inch = 3 'feet. 



Figure 2G. — Original Depression of the Granite Surface. 

 Due to erosion of a splieroidal mass. 



cliff shows toward the north end a sharp upward flexure of the contact 

 (figure 29). This is a less extreme example of the same t^'pe as the 



