Geology of Southern Part of the James Peak Quadrangle, Utah

• Main Author: Blau, Jan G.
• Format: Others
• Published: DigitalCommons@USU 1975
• Subjects: geology; southern; part; james; peak; quadrangle; utah; Geology
• Online Access: https://digitalcommons.usu.edu/etd/3783; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4788&context=etd

The mapped area, in north-central Utah, is centered about 22.6 miles south of Logan, Utah. It measures about 3.8 miles in the north-south direction and 6.6 miles in the east-west direction. Stratigraphic units of Precambrian and Cambrian age underline most of the area. The Precambrian units are as follows: (1) Maple Canyon Formation, (2) Kelley Canyon Formation, (3) Orthoquartzite unit, (4) Argillite unit, (5) Mutual Formation, and (6) Volcanic unit. The Brigham Formation, which overlies the Precambrian volcanic unit, is probably of Cambrian age; however, the lower part may be Precambrian. The overlying Cambrian carbonate unit is not differentiated. The Salt Lake Formation of Tertiary age overlaps older rocks in the valley north of James Peak. The western part of James Peak, east of a major normal fault, consists of east-dipping Precambrian units. The oldest unit, which crops out on the eastern side of Broadmouth Canyon, is the Maple Canyon Formation. The rocks of the eastern part of James Peak also dip generally eastward. A continuous stratigraphic section extends from the Kelley Canyon Formation, exposed in Wolf Creek Canyon, northeastward to the Brigham Formation. The Cambrian carbonate unit seems to overlie the Brigham in normal stratigraphic succession. A thrust fault, which has about 1,000 feet of displacement, is present on the eastern side of James Peak. Another thrust fault, on the southeastern side of James Peak, places the Cambrian carbonate unit on Precambrian units. A block of the Brigham Formation, near the southeastern corner of the area, is thrust over the carbonate unit and the Brigham. The thrust faulting is part of the Laramide Orogeny that occurred late in the Mesozoic Era and early in the Teritary Period. Movement was generally eastward. Normal faulting began early in the Tertiary Period and continues at the present time.