2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 1
Presentation Time: 1:30 PM

Gulf of Mexico Record of North American Tectonism and Landscape Evolution


GALLOWAY, W.E., Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78758-4445, galloway@mail.utexas.edu

Siliciclastic depocenters and reconstructed paleogeographies of the northern Gulf margin reflect and amplify the story of tectonism within the North American continent. Mesozoic drainage axes record four principal phases of continental drainage basin integration or reorganization:

1.Initially, syn-drift Jurassic fluvial systems arose in the remnant uplands of the southern Appalachian Mountains, and entered the northeast Gulf along the adjacent crustal sags.

2.By the Late Jurassic Cotton Valley depositional episode, a southeastward-flowing fluvial system, draining uplands in Colorado and New Mexico, created a new clastic depocenter within the East Texas basin. Multiple peripheral source areas were further rejuvenated by early Cretaceous intra-continental and basin-margin uplift at the termination of sea-floor spreading.

3.Cenomanian thermal uplift of the Mississippi embayment rejuvenated fluvial systems of the Woodbine/Tuscaloosa episode.

4.Southward migration of Laramide uplift filled the southern remnant of the Cretaceous foreland basin, and clastics began to spill over into the Maverick Basin by the late Campanian.

During the Cenozoic era, four major phases of continental uplift and erosion are recorded in the shifting patterns and rates of supply:

1.Palaeocene through middle Eocene pulses of Laramide uplift along the Central and Southern Rockies and Sierra Madre Oriental supported the early Cenozoic depositional episodes.

2.Late Eocene through Oligocene crustal heating, volcanism, and uplift of much of central Mexico and the southwestern United States nourished major Oligocene through early Miocene depositional episodes.

3.Initiation of erosion during the early to middle Miocene of the Cumberland Plateau and Appalachians invigorated supply to the east-central Gulf basin.

4.Pliocene uplift of the western High Plains rejuvenated north-western sources and created a broad eastward slope that converged with the west-sloping alluvial apron of the eastern interior.