Date of Award:


Document Type:


Degree Name:

Master of Science (MS)



Department name when degree awarded


Committee Chair(s)

J. Stewart Williams


J. Stewart Williams


Clyde T. Hardy


Wellsville Mountain is 10 miles west of Logan, Utah, at the northern extremity of the Wasatch Range. Paleozoic rocks form a northeast-dipping homocline bounded in part by northwest-trending high-angle faults and cut by a series of northeast-trending high-angle faults. A major transverse fault, with a stratigraphic displacement of 4,500 feet, divides the mountain into two distinct blocks.

The rock units of the area are comparable to those of the Logan quadrangle immediately to the east. Pre-Cambrian rocks crop out in Box Elder Canyon, just east of Brigham City, and are overlain by at least 20,000 feet of northeast-dipping Paleozoic rocks of every period except possibly the Permian. The Beirdneau sandstone member of the Jefferson formation of Devonian age and the Leatham formation of Lower Mississippian age are not recognized in the area. A new fauna, in the Jefferson formation, is tentatively correlated with that of the upper Devils Gate limestone of central Nevada. About 6,600 feet of the Oquirrh formation of Pennsylvanian age is exposed near the northern end of Wellsville Mountain. The presence of Desmoinesian fusulinids at the base of the Oquirrh and upper Virgilian fusulinids throughout the interval from 1,000 to 2,000 feet above its base indicates an absence of Lower Pennsylvanian rocks and suggests that the upper 4,400 feet may be in part Permian. Mesozoic rocks are not found in the area. The Wasatch formation and Salt Lake group of Tertiary age crop out in the foothills at the northern end of Wellsville Mountain.

Two fault systems are recognized in the area. The northeast-trending high-angle transverse faults of Laramide age and the north-west-trending high-angle bordering faults are Basin and Range age.



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