Chapter 5 - Cenozoic Depositional History 1

Summary

The Laramide orogeny, which extended along the length of North America, had both direct and indirect impacts on the Gulf of Mexico basin. Along the western Gulf margin, compressional deformation created a series of uplands and foreland troughs. Gravity transport systems constructed sandy slope/basin aprons in the troughs. To the north, tectonic uplands of the Western Interior supplied sediment to several evolving continental river systems that flowed southeastward into the northern Gulf. There, large delta systems prograded the coastal plain, shore zone, shelf, and continental slope tens of kilometers beyond the inherited Cretaceous shelf margin. Four principal depositional episodes are recorded in the stratigraphy of the northern margin: the Paleocene Lower Wilcox and Middle Wilcox, the early Eocene Upper Wilcox, and the Middle Eocene Queen City and Sparta. Sediment supply and construction of basinal submarine fan systems peaked in the Paleocene, and then decreased as supply waned in the Early Eocene.