Award Date

5-2012

Degree Type

Thesis

Degree Name

Master of Science in Geology

Department

Geoscience

First Committee Member

Andrew Hanson, Chair

Second Committee Member

Brenda Buck

Third Committee Member

Rodney Metcalf

Graduate Faculty Representative

Spencer Steinberg

Number of Pages

69

Abstract

The Muddy Creek Formation (MCF) may represent an ancestral Colorado River deposit. To test this hypothesis, I mapped exposures of the MCF within the Virgin River Depression (VRD), a rift basin in the central Basin and Range. This is the first study to analyze fluvial MCF facies and test their viability as ancestral Colorado River deposits.

Mapping, paleocurrent analysis, conglomerate provenance, and architectural elements analysis were used in order to characterize the fluvial MCF near Overton NV. Architectural elements analysis revealed that MCF fluvial facies are most closely associated with those of a high-energy sand-bed braided river system. These results do not resemble definitive Colorado River deposits. In light of these findings, fluvial facies of the MCF may be attributed to a Miocene Virgin River and permit a revised depositional model for the MCF within the VRD. Additionally, these findings inform models of dryland fluvial systems in rift basins.

Keywords

Basin and range; Braided river; Earth sciences; Great Basin; Miocene Geologic Period; Rift basin; Rifts (Geology); Muddy creek formation; United States – Virgin River; Virgin River depression

Disciplines

Earth Sciences | Geology | Geomorphology | Sedimentology

Language

English

Comments

Attached file: Plate 4.1

Attached file: Plate 4.2

Attached file: Plate 4.3

Plate4_1Swenberg.pdf (13585 kB)
Plate 4.1

Plate4_2Swenberg.pdf (16256 kB)
Plate 4.2

Plate4_3Swenberg.pdf (92299 kB)
Plate 4.3


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