422 J, W. Powell—Types of Orographie Structure. 
ridge-like structure is obseured. Many of the ridge-like moun- 
tains of the Basin Province have this structure. Such a ridge 
is composed of monoclinal strata, the one side presenting a bold 
escarped front, the other a more gently sloped back conforming 
The tract is drained by Salina Creek, which 
Diverse Displacement. The area represented 
unites its branches in the center and flows through the cafion on the left. 
The base line shows the sea-level. 
is six miles square. 
Fie, 4.—Bird’s-eye view of a portion of the Musinia Zone of 
to a greater or less degree with the dip. Sometimes the ridges 
themselves are faulted longitudinally, transversely or obliquely, 
and the faults may be slight or of great magnitude; but the | 
more common structure is a simple ridge with slight transvers? 
or oblique faults. 
