193 Advances and Applications in Geochronology for Interpreting Stratigraphic and Basin Records (Posters)

This session welcomes submissions related to applications of geochronology (e.g., U-Pb, 40Ar/39Ar) in stratigraphic research, including topics such as eruption and maximum depositional age estimation, provenance analysis, numerical modeling of geochronological data, and multi-disciplinary chronostratigraphic characterization.

Tuesday, 21 October 2025
8:00 AM - 5:30 PM
HBGCC, Hall 1

Detrital Zircon U-Pb Geochronology of the Eocene Clairborne Group of the northern Mississippi embayment, western Tennessee

Paper number: 193-15
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

The Mississippi embayment, a southward-plunging trough forming the northernmost extent of the Gulf Coastal Plain, has acted as a major sediment routing corridor to the Gulf of Mexico from the Cretaceous through the present. The Claiborne Group of western Tennessee, comprised of the Memphis Sand, Cook Mountain Formation, and Cockfield Formation, records sedimentation through the Eocene and is an important aquifer to the mid-South. However, limited outcrop exposure, local tectonic deformation, and lithologic similarity among units complicate efforts to resolve stratigraphic relationships in the subsurface.

This study integrates detrital zircon U-Pb geochronology, analyzed via LA-ICP-MS, with a lithologic and stratigraphic data from rotary sonic cores extracted from boreholes along a northeast-southwest transect across western Tennessee. Samples targeting fine to coarse sand across facies transitions and unconformities to constrain sediment sources, paleo-drainage divides, and maximum depositional ages (MDAs). These new data provide the first detrital zircon provenance framework for subsurface Claiborne Group sediments in the northern Mississippi Embayment.

Preliminary results reveal a shift in detrital zircon age spectra in the upper Memphis Sand and the overlying Cockfield Formation, indicating a reorganization of sediment routing pathways in the late Eocene. MDAs provide key chronostratigraphic constraints on Claiborne Group and allow bracketing of genetically related depositional episodes. These findings offer new insight into continental-scale drainage evolution and improve understanding of the temporal and spatial variability of source terranes through the ancestral Mississippi sediment routing during the Eocene.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-414903

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