Publication Date

1986

Document Type

Dissertation/Thesis

First Advisor

Weiss, Malcolm P. (Malcolm Pickett), 1921-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Geology

LCSH

Geology--Utah--Sanpete County; Geology--Utah--Juab County

Abstract

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.

Comments

Bibliography: [236]-244.

Extent

xvi, 246 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

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