Structural Analysis of the Laurentian Basement underlying the Black Warrior Basin using Geophysical Models

Session: Geoscience and Hydrogeology in the AI Era: From Predictive Models to Real-Time Applications (Posters)

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Abstract:

     The crustal structure of southeast Laurentia is related to processes that occurred from the Mesoproterozic to the Cretaceous. Following the Mesoproterozoic terrane accretion during the granite rhyolite province formation, Grenville orogeny assembled Rodinia producing intrusions and crustal thickening along the eastern – southeastern margins. The Neoproterozoic – earliest Cambrian rifting and fragmentation of Rodinia created the Laurentian margin outlined with normal faults segmented by transform faults. The Reelfoot Rift, an early Paleozoic NE-SW striking aulacogen, was truncated by the AL-OK transform fault.

     The early Paleozoic Laurentian passive margin transgressive sequences overlie the Precambrian Laurentian basement and are overlain by the Late Paleozoic sediment deposited into the NE-SW trending Black Warrior Basin. The basin homocline extends from the Nashville Dome to the syntaxial bend between the Appalachian and Ouachita thrust belts. The purpose of this project is to utilize gravity and magnetic data to investigate the crustal structure of the underlying basement, identify deformations and/or intrusions, and interpret overprinting from repeated tectonic events.

     Bouguer gravity and residual gravity anomaly maps indicate NE-SW trending gravity maxima with sources between 11.25 and 37.5 km based on upward continuation maps. These gravity maxima correlate with magnetic maxima on both reduced to the pole and residual magnetic maps which suggests the sources are linear mafic bodies underlying the Black Warrior Basin sediment. 2D forward modeling along-strike the parallel linear bodies reveals that the gravity and magnetic maxima distal to the Grenville front are greater than the proximal. Forward modeling along the NW – SE transect orthogonal to these linear bodies highlights deformation of structures from the Late Paleozoic continental collision.  

Keywords:  Laurentia, Rodinia, gravity/ magnetic anomalies, Grenville front, Reelfoot Rift

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

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