Sedimentology and sulfur isotope geochemistry of Green River Formation (Eocene), Uinta Easin, Utah Piceance Creek Basin, Colorado

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Publication Type dissertation
School or College College of Mines & Earth Sciences
Department Geology & Geophysics
Author Cole, Rex Don
Title Sedimentology and sulfur isotope geochemistry of Green River Formation (Eocene), Uinta Easin, Utah Piceance Creek Basin, Colorado
Date 1975-06
Description The Green River (Eocene), Uinta (Eocene), and Wasatch (Paleocene-Eocene) Formations in the Uinta and Piceance Creek Basins represent sedimentary rocks deposited in fluvial and lacustrine environments associated in and around ancient Lake Uinta, Study of the sedimentologic characteristics of 271 polished slabs of oil shale and other fine-grained rocks demonstrates that eleven descriptive classes of primary stratification and six classes of secondary structures are common, Primary and secondary structures vary with lith- ology and stratigraphic position, A correlation exists between the stratification characteristics of oil shale and its organic content. Pyrite, marcasite, and pyrrhotite are the most common sulfide minerals, Pyrrhotite is present only in oil shale. Marcasite was the most common sulfide mineral deposited with oil shale, but has generally recrystallized to pyrite. Sulfur isotopic ratios of the sulfides show a range of delta34S values from -12,6 to 66.6 permil, a total spread of 79.2 permil. Sulfides in fluvial and nearshore lacustrine rocks have wide delta34S distributions and mean values near 15 34 permil, Sulfides in oil shale have narrow delta34S distributions and average about 35 permil. No correlation was found between the delta34S values of the sulfides and the sulfide mineralogy. A poor correlation was found between the delta34S values of sulfides and the mineralogy of the host rocks. A good correlation was found between the delta34S of sulfides and the organic content of the host oil shale. Values of with lateral position. The variation is most pronounced in sandstone and poorly stratified marlstone, and is least pronounced in oil shale. Sulfides show delta34S cation intervals, and correlate with variations in lithology suggesting environmental control. Stratigraphic variation of delta34S through the Parachute Creek Member of the Green River Formation shows that sulfides are most enriched in 34S in the Mahogany zone. Sulfides in fluvial rocks of the Wasatch Formation, the Douglas Creek Member of the Green River Formation, and the Uinta Formation in the Piceance Creek Basin are the most depleted in 34S. Lacustrine rocks in the Green River Formation, especially in the Parachute Creek Member, have the most 34S-enriched sulfides. A depositional model for Lake Uinta is generated to explain the delt34S variations from one environment to another (mudflat to offshore lacustrine) by the activity of sulfate- reducing bacteria existing in areas with steady and unsteady sulfate supplies.
Type Text
Publisher University of Utah
Subject Rocks, Sedimentary; Sediments (Geology) -- Uinta Basin (Utah and Colo.); Sediments (Geology) -- Colorado -- Piceance Creek Basin; Thesis and dissertation georeferencing project
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Relation is Version of Digital reproduction of "Sedimentology and sulfur isotope geochemistry of Green River Formation (Eocene), Uinta Easin, Utah Piceance Creek Basin, Colorado" J. Willard Marriott Library Special Collections, QE3.5 1975 .C57
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
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Identifier us-etd3,12839
Source Original: University of Utah J. Willard Marriott Library Special Collections
Conversion Specifications Original scanned on Epson GT-30000/Epson Expression 836XL as 400 dpi to pdf using ABBYY FineReader 9.0 Professional Edition.
ARK ark:/87278/s60p1dq5
Setname ir_etd
Date Created 2012-04-24
Date Modified 2012-09-24
ID 194302
Reference URL https://collections.lib.utah.edu/ark:/87278/s60p1dq5