Highly seasonal and perennial fluvial facies: implications for climatic control on the Douglas Creek and Parachute Creek Members, Green River Formation, Southeastern Uinta Basin, Utah

Update Item Information
Publication Type thesis
School or College College of Mines & Earth Sciences
Department Geology & Geophysics
Author Gall, Ryan D.
Title Highly seasonal and perennial fluvial facies: implications for climatic control on the Douglas Creek and Parachute Creek Members, Green River Formation, Southeastern Uinta Basin, Utah
Date 2017
Description The early to middle Eocene Green River Formation consists of continental strata deposited in Laramide ponded basins in Utah, Colorado, and Wyoming. This study (1) documents fluvial and lacustrine strata from the Douglas Creek and Parachute Creek Members of the middle Green River Formation, southeastern Uinta Basin, Utah, and (2) uses new interpretations of the link between climate and fluvial sedimentary expression to interpret the terrestrial evolution of early Eocene climate. The stratigraphy was analyzed via outcrops along a 10 km transect in Main Canyon on the Tavaputs Plateau, and is divided into three distinct, stratigraphically separated depositional settings: (1) the lowermost Interval 1 is dominated by amalgamated sandstone channels that contain 70-100% upper flow regime sedimentary structures. The channels are interpreted to represent fluvial deposits controlled by a highly seasonal climate, where most deposition was limited to seasonal flooding events. (2) Interval 2 is dominated by alternating siliciclastic and carbonate lacustrine deposits, interpreted as local pulsed fluvial siliciclastic input into shallow Lake Uinta, and periods of fluvial quiescence represented by littoral carbonate deposition. (3) The uppermost Interval 3 is dominated by erosively-based, trough cross bedded sandstone channels interbedded with littoral lacustrine and deltaic deposits. The Interval 3 sandstone channels are interpreted as perennial fluvial deposits with relatively little variation in annual discharge, akin to modern humid-temperate fluvial systems. The stratigraphic transition from seasonally-controlled (Interval 1) to perennial (Interval 3) fluvial deposits is interpreted to represent a fundamental shift in Eocene climate, from the peak hyperthermal regime of the Early Eocene Climatic Optimum (EECO) to a more stable post-EECO climate.
Type Text
Publisher University of Utah
Subject Geology; Geophysics
Dissertation Name Master of Science
Language eng
Rights Management (c) Ryan D. Gall
Format Medium application/pdf
ARK ark:/87278/s6nd0drc
Setname ir_etd
ID 1404476
Reference URL https://collections.lib.utah.edu/ark:/87278/s6nd0drc