Date Thesis Awarded

5-2009

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Geology

Advisor

Christopher M. Bailey

Committee Member

Randolph M. Chambers

Committee Member

James M. Kaste

Committee Member

Karen M. Layou

Abstract

A heterogeneous, 700-1000 m thick sedimentary sequence is exposed beneath Oligocene-Miocene volcanic rock that cap the Fish Lake Plateau in south-central Utah. These units range in age from late Cretaceous to Eocene and include the Price River, North Horn, Flagstaff, and Colton formations. This study describes the distribution and environmental significance of these strata. The Cretaceous Price River Formation (180-300 m) is a fine-to-coarse, buff sandstone with minor sandy shale and organic-rich shale. It varies from thinly bedded to massive, with local high-angle cross-bedding. The late Cretaceous-Paleocene North Horn Formation (215-300 m) consists of variegated shale and mudstone, gray to brown sandstones, local chert pebble conglomerate, and yellow-gray thinly bedded micrite. The Paleocene-Eocene Flagstaff Formation (245-365 m) consists of light-gray and yellow carbonate that ranges from crystalline to argillaceous in thin to thick beds, but is locally a massive cliff-former. It is interbedded with gray-green shale and red calcareous siltstone, and has local algal nodules and oncolites. The Eocene Colton Formation (60 m) consists of deep-red to variegated shale and yellow-buff sandstone with minor carbonate mudstone and bentonite. A massive to cross-bedded chert pebble conglomerate with interbedded minor lithic sandstone sits above the Colton in some locations, and may be correlative to the Eocene Crazy Hollow Formation that crops out to the north of the Fish Lake Plateau. These units represent a transition from high energy fluvial to lacustrine environments. The Price River Formation was deposited in a fluvial/marine environment, and the North Horn a fluvial/lacustrine environment. The Flagstaff and Colton formations both are interpreted as lacustrine deposits, that vary between freshwater and highly saline carbonate lakes. The lacustrine nature of this sequence is confirmed by the presence of fossil ostracods and mollusks, pollen from the Taxodiaceae, oncolites, and siliciclastic and carbonate composition. Variation in these units reflects regional tectonic uplift and climate change during the Paleogene.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Comments

Thesis is part of Honors ETD pilot project, 2008-2013. Migrated from Dspace in 2016.

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