Identifier

etd-06082010-004937

Degree

Master of Science (MS)

Department

Geology and Geophysics

Document Type

Thesis

Abstract

The discovery of a terrestrial mammalian fauna in the Miocene deposits on Fort Polk, Louisiana, fills a geographic gap in the Gulf Coast paleontological framework, but the provenance of the fossils, nature of the depositional environments, and relationships between the sites is still debated. This is especially true for the TVOR site cluster. TVOR SE has a mixture of marine and terrestrial vertebrates in association with a partly dissolved, in situ bed of articulated oyster shells, which stands in contrast to the fully terrestrial and freshwater assemblage at TVOR, and the indeterminate site TVOR S. Although limited outcrop may bias the observed fossil assemblages, it is thought that the differing characteristics of the sites are related to changing depositional environments. Taphonomic and geologic data were integrated to create a more complete picture of the paleoenvironmental factors contributing to the formation of the fossil sites. One core each was collected at TVOR S and TVOR SE, and these were studied along with a core previously collected at TVOR site. Magnetic susceptibility (MS) work on the cores suggested correlation between the TVOR S and TVOR SE sites, and possible correlation between TVOR S and TVOR. MS data indicated marine influence at all three sites, including TVOR, which previously had been considered fully terrestrial. Heavy mineral analysis was unfruitful regarding the provenance of the sites. Identified, curated fossils from the sites were assigned to bone dispersal groups to assess the degree of sorting in the fossil assemblages, and it was discovered that the vast majority of both macro- and micro-vertebrate fossils fall into Groups I and II, indicating that the fossil assemblages are the result of transport into the sites rather than attrition of local biota. The geological, geophysical, and paleontological records of the sites give a picture of a quiet, distal, setting just beginning to reflect environmental changes spurred by local and global geologic processes.

Date

2010

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Schiebout, Judith A.

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