ABSTRACT: Implications of Regional Salt Distribution on Gulf Coast Basin Architecture

SIMMONS, GREGORY R., and JOEL S. WATKINS, Texas A&M University, College Station, TX

The Gulf of Mexico basin accumulated great thicknesses of evaporites during its early tectonic history. Sea floor spreading in the central Gulf separated the extensive evaporites into northern and southern provinces. The distribution of salt in the northern Louann province reflects a complex interplay between tectonic basin architecture and subsequent salt kinematics. Persistent northwest trends are attributed to a crustal fabric believed to be the dominant direction of Mesozoic extension. Major transfer faults evident as prominent lineations divide the Gulf Coast margin into segments characterized by markedly different salt abundances and structural styles.

The Perdido and Mississippi Fan foldbelts formed in response to compressional forces transmitted via shelf margin growth faults to the basinward limit of Louann salt. This limit is presumed near the continent/ocean boundary. Major depocenters developed landward of and at about the same time as foldbelt deformation. Allochthonous overthrusts of the Perdido and Mississippi Fan foldbelts appear to be on the order of 1 to 10 km. The Brazos and Sabine transfer faults offset the foldbelts in a right-lateral sense. An abundance of structurally oriented salt ridges within the intervening corridor possibly indicates a series of right-lateral offsets of the continent/ocean boundary. The Sigsbee bulge consists of a salt-wedge complex overthrusting seaward from the Brazos-Sabine corridor up to 60 km.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)