A Discussion of Certain Geologic Features of the Wasatch Mountains

This paper discusses: (1) an 18-mile section of the Wasatch Front Range east of Salt Lake City, (a) The Wasatch fault is an initial fault-scarp modified by erosion and not a fault-line scarp, (b) The area is complexly folded and faulted, (c) Differences in the pre-Cambrian rocks at the north and south ends of the section are pointed out and the younger rocks are correlated with the rocks in the Cottonwood and Park City districts. (2) Rock Creek Canyon near Provo exposes an overturned anticline which probably has an important bearing on the structure of that section of the Wasatch Mountains. (3) Cache Valley, the depression between the Wasatch Front and Bear River ranges, is a down-faulted block and not a syncline as shown on geologic maps. (4) The folds and probably the thrust faults in the Wasatch Mountains were developed at the close of the Cretaceous or early Tertiary periods. The Wasatch and other major normal faults of the area were probably initiated near the middle of the Miocene, and the later movements have been along the old lines. (5) The conclusions of the writer regarding the east rim of the Great Basin substantially agree with conclusions regarding the western part of the Great Basin presented in a recent paper by Louderback.