GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 218-2
Presentation Time: 1:50 PM


FREDERICK, Bruce C., Geology Department, University of Kansas (KU), 1414 Naismith Drive, Room 254, Lawrence, KS 66045, BLUM, Mike D., Department of Geology, The University of Kansas, 1414 Naismith Drive, Room 254, Lawrence, KS 66045 and SNEDDEN, John W., Institute for Geophysics, Univ of Texas at Austin, JJ Pickle Research Campus, Bldg 196 (ROC), 10100 Burnet Rd (R2200), Austin, TX 78758-4445

The Late Triassic to Early Jurassic marks a period of significant synrift extensional tectonics in the Gulf of Mexico basin that accompanied increasingly dynamic sediment drainage pathways from source to sink. Because much of the Eagle Mills and coeval siliciclastic sedimentary formations between Mexico and the Atlantic seaboard are not exposed in outcrop, Early Mesozoic basin-scale sediment routing models depicting paleodrainage network configurations from upland source areas to deep basinal sinks remain poorly constrained. Here we present: 1) 3,294 new detrital zircon U-Pb analyses from 16 Late Triassic to Early Jurassic pre-salt, clastic, subcrop samples; and 2) the first comprehensive basin-scale isopach and structure-contour maps based on over 14,000 linear kilometers of 2D seismic reflection data and more than 2,300 geophysical well logs spanning the northern Gulf of Mexico margin from Florida to the Texas/Mexican border to elucidate sediment provenance and paleodrainage systems. Local tectonism, including uplifted and sutured source terranes such as the Sabine, Monroe, Wiggins, Suwannee, East Mexico Arc, and Yucatan/Maya blocks, are shown to have had a substantial impact on sediment routing dynamics and provenance signatures. These detrital zircon U-Pb analytical results, in conjunction with pre-salt sedimentary structure, isopach, and historical geochronological dataset appraisal, reveal a series of smaller, dynamic, regional paleodrainage networks leading to paleo-Gulf of Mexico and paleo-Pacific margins with significant implications for reservoir and source rock extent in the southern Gulf of Mexico pre-salt exploration.