Masters Theses

Keywords and Phrases

Biogenic; Continental Shelf; Heterogeneity; Pelagic; Tractional; Unconventional Reservoir


"The Upper Cretaceous Tuscaloosa Marine Shale (TMS) is an unconventional shale reservoir deposited on the continental shelf of the northern Gulf of Mexico Basin. Previous studies have focused on sequence stratigraphy, thermal modeling, and well-log correlations. However, a limited understanding of the stratigraphic heterogeneity of the TMS is yet to be studied. This study aims to characterize the stratigraphic heterogeneity of the TMS using core, petrographic, and well-log analyses to better understand the depositional conditions and processes that occur on the continental shelf. The TMS has been classified into four lithofacies of very fine sands – coarse silts (LF1), medium-fine silt (LF2), fine silt–clay (LF3), and microbial-algal deposits (LF4). LF1 is characterized by an erosional base and well-developed stratification, indicating tractional deposition by density currents. LF3 is characterized by a sharp or gradational base and sub-mm planar laminations, interpreted as pelagic deposits. LF2 is transitional between LF1 and 3. LF4 is characterized by a sharp or gradational base and discontinuous, poorly defined, pyrite and calcite replaced wavy laminations, interpreted as biogenically influenced deposits or organic. XRD analyses suggests variations in minerals, such as quartz, calcite, and total clay in all LF. The variability in mineralogy and sedimentary fabrics suggests that conditions on the continental shelf were oxygenated and later became anoxic, depositing organic-rich shales. Weak relationships in LF and wireline logs were found, suggesting challenges in identifying LF in wireline log signatures. The results of this study can improve the LF classification of the TMS and the understanding of depositional processes and conditions on the continental shelf"--Abstract, p. iii


Yang, Wan
Borrock, David M.

Committee Member(s)

Wronkiewicz, David J.


Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology


Missouri University of Science and Technology

Publication Date

Fall 2022


xii, 174 pages

Note about bibliography

Includes_bibliographical_references_(pages 168-173)


© 2022 Efren Mendez Jr., All Rights Reserved

Document Type

Thesis - Open Access

File Type




Thesis Number

T 12201

Included in

Geology Commons