Date of Award
1-1-2025
Document Type
Thesis
Degree Name
M.S. in Engineering Science
First Advisor
Jennifer N. Gifford
Second Advisor
Brian F. Platt
Third Advisor
Inoka Widanagamage
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
The Mississippi Embayment (MSE) is a wedge-shaped ~259,000 km2 southward-plunging basin in the Gulf Coastal Plain that extends from southern Illinois and fans out into parts of AL, AR, KY, LA, MS, MO, TN, and TX. It is filled with Cretaceous (~145.5 to 65.5 Ma) to recent strata. Cretaceous deposits in the western Mississippi Embayment (WMSE) are significant for establishing sediment accumulation and dispersal patterns during and after the reactivation of the late Proterozoic and early Paleozoic Reelfoot rift system at the end of the Mesozoic Era. We report a petrographic study and U-Pb ages of detrital zircons in unlithified sands from Cretaceous deposits in the WMSE to track their provenance and interpret sediment transport pathways and sediment sources. Observations of these unlithified sands reveal dominant quartz, sedimentary lithics, few feldspars, micas, and detrital matrix with clay minerals like glauconite, minor rutile, and magnetite in the heavy fraction. The zircon morphology ranges from sub-rounded to well-rounded and euhedral crystals, which are clear and display colors ranging from pale yellow to purple. U-Pb analysis of zircon grains (n=792) yields a broad age spectrum ranging from ~63 Ma to >3500 Ma, with a notable population between ~67–76 Ma. These younger zircons may indicate a local volcanic source, likely linked to the Jackson Dome or Paleogene intrusions in the Gulf region. Older age peaks suggest derivation from Appalachian and Grenville-aged terranes, while the role of the Ouachita Mountains remains ambiguous, which potentially acts as either a primary source or a conduit for recycled sediment from older basins such as the Illinois Basin to the north.
The Cretaceous sands in the WMSE were derived from a combination of local volcanic sources and reworked material from nearby orogenic belts and intracratonic basins. These findings provide new constraints on Late Cretaceous to early Paleogene sediment routing systems and contribute to a better understanding of tectonically influenced basin evolution in southeastern North America.
Recommended Citation
Sapkota, Sagar, "Petrography and Detrital Zircon Geochronology of Cretaceous Sands: Implications for Provenance in Western Mississippi Embayment" (2025). Electronic Theses and Dissertations. 3380.
https://egrove.olemiss.edu/etd/3380