Date of Award
Master of Science - Geology
R. LaRell Nielson
Sediment gravity flows into deep-water environments are important stratigraphic traps in lithologically diverse reservoirs generating multiple plays for hydrocarbon exploration. These highly heterogeneous deposits can be studied by utilizing chemostratigraphy and higher-order sequence stratigraphy; being an accurate method for reservoir characterization. Studying these gravity flows along a carbonate platform’s slope can further expand an understanding of the stratigraphy that is filling adjacent basins. The application of elemental analyses can support in identifying mineralogy that impact reservoir quality, especially when conventional testing cannot be applied.
This study utilizes five cores containing the Wolfcamp Formation from the southeastern slope of the Central Basin Platform in northwest Crockett County, Texas. High resolution chemostratigraphy was conducted using X-ray fluorescence along with total organic carbon, X-ray diffraction, and scanning electron microscope at resolutions based on chemofacies defined by hierarchical clustering analyses. Interpretation of chemofacies, mineralogy, organic matter, gravity flows, and sequence cycles is used to evaluate depositional conditions due to periodic glacioeustasy and episodic sea-level fluctuations and tectonic pulses along the carbonate platform margin of the Wolfcamp Formation.
The study area can be divided into eight facies: (1) bioclast packstone to grainstone, (2) porous bioclast packstone to grainstone, (3) lithoclast rudstone to floatstone, (4) bioclast to lithoclast wackestone, (5) mixed carbonate mudstone, (6) mixed siliceous mudstone, (7) clay-rich argillaceous mudstone, and (8) argillaceous-siliceous mudstone. Gravity flows and depositional processes are characterized: (1) slides to slumps, (2) debris flows, (3) turbidity currents, (4) hemiturbiditic plumes, and (5) hemipelagic deposition. Mudstones associated with gravity flows along the slope are organically-rich (4.65% mean TOC) due to the preservation of organic matter from: (1) organic matter supply, (2) rapid burial, and (3) disoxic conditions.
Blizzard, Alex and Bloxson, Julie, "Chemostratigraphy of Carbonate Gravity Flows of the Wolfcamp Formation in Crockett County, Midland Basin, Texas" (2020). Electronic Theses and Dissertations. 334.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Tell us how this article helped you.