Author ORCID Identifier

https://orcid.org/0000-0002-0088-1368

Date Available

7-12-2020

Year of Publication

2019

Degree Name

Master of Science (MS)

Document Type

Master's Thesis

College

Arts and Sciences

Department/School/Program

Earth and Environmental Sciences (Geology)

First Advisor

Dr. Andrea Erhardt

Abstract

The Late Paleozoic Ice Age represents a dynamic period in Earth system history recording a shift from icehouse to greenhouse conditions. Concomitant with this change was a series high-frequency, high-amplitude sea level fluctuations leading to the deposition of “Kansas type” cyclothems in the Mid-Continent, and a similar rhythmic expression of interbedded shales and carbonates in the Midland Basin. Stable isotope geochemistry is a particularly powerful tool when examining these mud-rich successions because changes in organic matter partitioning may be recorded first in δ13CDIC of sea-water and consequently in δ13Ccarb of marine rocks. The δ13Ccarb record may also illuminate early and late-stage diagenetic processes and associated destruction of organic matter.

This study used high-resolution x-ray fluorescence (XRF) and δ13Ccarb measurements to analyze paleo-environmental conditions in two cores within the Midland Basin Wolfcamp Formation. Using this approach, the combination of more positive δ13Ccarb measurements and enrichment of redox-sensitive elements reflect conditions more favorable for organic matter enrichment in the distal core. Additionally, four (< 6 in.) early-diagenetic intervals have been identified representing prolonged periods of reduced or non-deposition based on sharp negative δ13Ccarb excursions. These horizons are proposed as potential chronostratigraphic tie-points between the two core localities.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2019.276

Funding Information

Funding for this research was provided by Pioneer Natural Resources USA, Inc.

Funding for this research was provided by the Geological Society of America.

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