SOUTHERN WASATCH MOUNTAINS, UTAH 447 
Sevier Desert in June, 1912, but none farther east are known save 
this obscure Provo occurrence. 
THE SANTAQUIN-MOUNT NEBO DISTRICT 
Santaquin is about 18 miles S.S.W. of Provo. The Wasatch 
Range from here southward to Mount Nebo is interesting both 
from a stratigraphic and structural standpoint. 
Stratigraphy.—The oldest formation in the district is a band of 
pre-Cambrian gneissoid granite with large included bodies of schists, 
exposed for 2 miles or more along the lower range from east of 
Santaquin. It is quite different in texture from the granite of the 
Cottonwood district, and is overlain unconformably by Cambrian 
quartzite, the basal beds of which contain quartz and coarse red 
feldspar fragments derived from the pegmatitic facies of the granite. 
The quartzite formation dips 28° east and does not appear to be 
over 800 ft. thick. It varies in texture from conglomerate to shale, 
and in color from white to dark red and brown. In its upper half 
are a few dark-green beds with a high iron content. The quartz- 
ite passes upward into shale in which Cambrian trilobites have 
been found. The shale is followed by alternating beds of argil- 
laceous limestone and shale, and finally by continuous limestone 
which at the top of the ridge includes a part of the upper Mississip- 
pian “intercalated series.” 
The Mississippian limestone is abundantly fossiliferous, and 
the lowest Mississippian fossils were found at a horizon about 2,400 
ft. above the top of the quartzite. No fossils in the intervening 
limestones were found, but the lithologic succession as a whole is 
very similar to that of the lower half of the limestones of the Tintic 
district, about 20 miles to the southwest, which total 3,500 ft. in 
thickness and are chiefly or wholly Cambrian. No unconformity 
was detected, but so far as comparisons can be made the Missis- 
sippian limestones in the Santaquin, as well as in the Cottonwood 
district, lie on a much thinner series of limestone than is the case 
in the Tintic district to the west or in the northern Wasatch Moun- 
tains. 
The upper Mississippian ‘intercalated series’ is overlain 
unconformably on the east flank of the ridge by a coarse reddish 
