SOUTHERN WASATCH MOUNTAINS, UTAH 451 
with gentle easterly dip forms the low western ridge, and the pre- 
Mississippian limestones lie directly opposite on the west face of 
the main ridge. The “‘intercalated series”’ forms the crest of the 
main ridge, about 2,000 ft. above the western ridge. To the south 
across Wash Canyon, which follows a nearly E.-W. fault, the “‘inter- 
calated series” is followed by Cambrian quartzite and limestones, 
and farther south a second E.-W. fault cuts off the Green Canyon 
overthrust. To the north, the ‘intercalated series”’ of the western 
ridge abruptly gives way, at another E.-W. fault, to the Eocene 
sediments and later volcanic breccia, which cover the low hills 
west of Santaquin Canyon, whereas the face of the main ridge east 
of the canyon is made up of the pre-Cambrian complex and lower 
Paleozoic strata, and the Tertiary beds are found only along its 
eastern base. The most obvious E.-W. (N. 70° E.) fault in the 
district is on the west side of the main ridge in a ravine just north of 
Santaquin Canyon, where the entire Cambrian quartzite and the 
overridden Mississippian limestone beneath it are cut off and fol- 
lowed on the south side by the lower (probably Cambrian) lime- 
stone beds. 
It is of some interest to add that faulting later than the Tertiary 
volcanic flows was found by the writer last year in the East Tintic 
district and that this accords with the more convincing evidence in 
the Santaquin—Mount Nebo district, where the presence of faulted 
Eocene conglomerate and late or post-Eocene volcanic breccia places 
the time of the faulting and range uplifts not earlier than Miocene, 
thus confirming existing conclusions regarding the age of the basin 
ranges. 
SUMMARY 
In the Cottonwood district the ‘‘Ute” limestone and ‘‘Ogden”’ 
quartzite recognized by the Fortieth Parallel Survey are shown to 
be respectively parts of the Mississippian (and older) limestones 
and Cambrian quartzite. 
The latter has overridden the former along an overthrust fault 
of easterly dip. 
This overthrust is broken by at least two later reverse faults 
of westerly dip which were formed during the domal uplift induced 
by the granite intrusion. 
