SOUTHERN WASATCH MOUNTAINS, UTAH 445 
exposed thickness was not too great and no other quartzite occurred 
above them; but since they have the same stratigraphic position 
as do the fossiliferous Cambrian ‘‘upper’’ quartzite and shale in the 
Cottonwood district, there can be no reasonable doubt of their 
Cambrian age. There are several good exposures of shale just 
above the quartzite areas, and it is in these that fossils are to 
be expected. South of American Fork Canyon the strata pitch 
southward, and along the west foothills of Timpanogos Peak, east of 
Pleasant Grove, the Mississippian limestone reaches nearly or quite 
down to the level of the Lake Bonneville shore line. Timpanogos 
Peak was not ascended. 
THE PROVO DISTRICT 
As only one short day was spent at Provo, remarks will be 
limited to the two quartzite occurrences along the lower front of 
Provo Peaks. They are both exposed along anticlines which are 
in line with each other, but oppositely unsymmetrical. The 
northern exposure forms a low arch for about 3 miles along the range 
front, and is nearly bisected by the mouth of Rock Creek Canyon, 
northeast of Provo. Near the mouth of the Canyon the quartzite 
is flanked by a still lower body of dark argillaceous limestone, which 
at the mouth of the canyon is faulted against it. No fossils were 
found in the limestone, and its physical characters were of too 
indefinite and general a character to permit a definite correlation 
with any members of the great limestone belt above the quartzite, 
though such a correlation is possible. It is also possible that this 
lower limestone is intercalated within the quartzite. Pebbles of 
impure limestone were found in a dark conglomerate bed in the 
quartzite at the canyon mouth, but represented, on weathered 
surface, a light-gray, finely banded type and not the dark type 
in question. The pebbles, however, indicate the presence of lime- 
stone in Cambrian or earlier time, and an unconformity possibly 
within the Cambrian. 
The quartzite and its overlying shale have a gentle eastward dip 
for a short distance, but just above the mouth of the canyon they 
steepen abruptly and are slightly overturned, dipping 80° west- 
ward. ‘The great limestone belt lies above the overturned portion 
