Weiss, Malcolm P. (Malcolm Pickett), 1921-
M.S. (Master of Science)
Department of Geology
Geology--Utah--Sanpete County; Geology--Utah--Juab County
The Fountain Green North Quadrangle lies in an area of transition between three physiographic provinces in central Utah: the Middle Rocky Mountains, Basin and Range, and Colorado Plateau. The quadrangle's setting has resulted in the complex structure and geologic history which are expressed by the surface geology. Strata in the quadrangle range from Middle Jurassic to Quaternary in age. This study represents the first time that the Early Cretaceous Cedar Mountain Formation has been recognized in the quadrangle. The Late Cretaceous Indianola Group dominates the study area, and several problems involving it have been addressed. A tentative correlation of stratigraphic horizons in the Indianola Group, within and between the Gunnison Plateau and the cedar Hills, is proposed. The abrupt increase in thickness of the group from the Gunnison plateau to the Cedar Hills is attributed to erosion more normal to the disturbed bedding of the cedar Hills, and erosion subparallel to the relatively undisturbed bedding of the Gunnison Plateau. The structural discontinuity of the group from the Gunnison plateau to the Cedar Hills is believed to be the result of thrusting and the emplacement of the Nebo Allochthon during the latest Cretaceous. Mapping of Quaternary deposits, not addressed in previous studies, was given special attention. The only igneous intrusion in the study area, here named the Salt creek Dike, has been dated; it has yielded an age of approximately 33.6 + 1.4 million years. This date may help in timing the initiation of Basin and Range extension in central Utah. The structural deformation of the area is mostly the result of eastward migration of thrusting, which occurred during the Sevier Orogeny. Salt diapirism has only locally modified the structure within the quadrangle. The frontal fault system along the northeast margin of the Gunnison Plateau, in the study area, is believed to be younger than the frontal fault system to the south. This implies that the portion of Sanpete Valley in the study area is younger than the main valley to the south. Geologic hazards and economic geology have also been considered in this study.
Banks, Raymond L., "The geology of the Fountain Green North Quadrangle, Sanpete and Juab Counties, Utah" (1986). Graduate Research Theses & Dissertations. 5801.
xvi, 246 pages
Northern Illinois University
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