Mineralogy and Geology. 261 
paste; that is, originally, of igneous origin. Some of the tholoiel 
ks are ve 
1 the appe: 
Fort Bridger beds, of which Church Buttes is an example. 
The dip is nearly northwest, though the trend of this basaltic ridge 
: : : ms 
west and southeast, and another north and south. e tertiary 
7 e river cuts its way through an upheaved ridge 
Massive feldspathic granite, for three miles, betw walls from 
D 
the north side is extremely rugged, the immense projecting masses 
of granite forbiddi tation to gain a foothold. It would 
t Pag Derg Ribiog od sort of rift in the 
side is gashed out in a wonderfully picturesque mamner, so that 
isolated columns and peaks are left standing, while all the inter- 
di i away. This ridge will 
across th par. out: ‘om | 
southeast side that the ridges of upheaval, above described, incline. 
granite ridg: to form a sort of abrupt anticlinal. On 
the southeast side the rocks all are bare, or covered with a super- 
