Geology of the Sheeprock Mountains, Tooele and Juab Counties, Utah

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Title Geology of the Sheeprock Mountains, Tooele and Juab Counties, Utah
Publication Type thesis
School or College College of Mines & Earth Sciences
Department Geology & Geophysics
Author Cohenour, Robert E.
Date 1957-08
Description The Sheeprock Range, Tooele and Juab Counties, Utah, is composed chiefly of consolidated sedimentary rocks of Precambrian and Paleozoic age. Several areas of both intrusive and extrusive rocks are present. Unconsolidated sediments related to late Tertiary and Quaternary episodes cover much of the flanks of the range as pediment gravels, lake deposits, and alluvium. Nearly 11,000 feet of Precambrian metasediments, largely slates and quartzites similar to late Precambrian formations in central and western Utah, crop out in the central part of the area. Tillites similar to those found locally in the Wasatch Mountains are the thickest and most distinctive of the Precambrian rocks. Twenty-seven formations having a combined thickness of approximately 20,000 feet represent the Paleozoic era and include rocks of all Paleozoic periods excepting (?) Permian. Over 80 percent of the Paleozoic rocks are of marine origin, the remainder are continental-interior-shelf and shoreline deposits. Limestone, dolomite, quartzite, and shale typical of miogeosynclinal environment constitute the Paleozoic rock types. Excepting minor hiatuses, continuous sedimentation prevailed from Precambrian into Pennsylvanian. All formations were strongly folded and broken by thrust faults during the Laramide orogeny. Rock units necessary for precise relative dating of Laramide and later orogenic events are not present in the Sheeprock Range, but the relationships of preserved structures permit the establishment of a sequence of deformational phases as follows: (1) Cedar Hills orogeny(?) - Mid-Cretaceous phase, (2) Early Laramide orogeny - Montana phase, (3) Mid-Laramide orogeny (?) - Paleocene phase, (4) Late Laramide orogeny, and (5) Basin and Range phase. Structures formed during these phases include folds, thrust faults and imbrications, and normal faults, and the structures of each successive phase are superposed upon those of earlier phases. Igneous activity which began in early Tertiary and continued into Miocene formed granitic and monzonitic intrusions and extensive rhyolitic and andesitic flows. A single small area of basalt of undetermined age is present. The resulting structure of the Sheeprock Range is essentially a northward-dipping homocline modified by several folds, major thrusts, and intrusions. Normal faulting of the Basin and Range orogenic phase, concomitant with and following the igneous activity, affected both Tertiary and older rocks and is primarily responsible for the present topography and out¬ line of the Sheeprock Range. Lake Bonneville shoreline features along the western part of the area and a questionable morainal deposit at the mouth of North Oak Brush Canyon represent Pleistocene events. Mineral deposits fall into two major groups: (1) deposits associated with the West Tintic monzonite cutting Precambrian and Paleozoic rocks have yielded minor quantities of commercial ores of lead, zinc, silver, gold, and tungsten; (2) deposits associated with the Sheeprock granite have yielded ores and protores of beryllium, lead, silver, tungsten, thorium, and uranium, but none of these has achieved commercial significance.
Type Text; Image
Publisher University of Utah
Subject Geology -- Utah -- Sheeprock Mountains; Geology -- Utah -- Tooele County; Geology -- Utah -- Juab County; Thesis and dissertation georeferencing project
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Relation is Version of Digital reproduction of Geology of the Sheeprock Mountains, Tooele and Juab Counties, Utah, J. Willard Marriott Library Special Collections, QE 3.5 1957 C64
Rights Management In the public domain use of this file is allowed in accordance with the Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License, http://creativecommons.org/licenses/by-nc-nd/3.0/us
Format application/pdf
Format Medium application/pdf; image/jpeg
Identifier us-etd3,10495
Source Original: University of Utah J. Willard Marriott Library Special Collections
Conversion Specifications Text: Original scanned on Epson GT-30000/Epson Expression 836XL as 400 dpi to pdf using ABBYY FineReader 9.0 Professional Edition. Images: Original Scanned on Colortrac Smartlf GxT42 and saved as 300dpi tiff. Final display image generated by CONTENTdm.
ARK ark:/87278/s6668v18
Setname ir_etd
ID 195351
Reference URL https://collections.lib.utah.edu/ark:/87278/s6668v18
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