DETERMINING THE MID JURASSIC SEDIMENTATION PATTERNS AND BASEMENT ARCHITECTURE OF THE EASTERN GULF OF MEXICO

The eastern Gulf of Mexico (EGoM) has not received as much attention as the western Gulf of Mexico despite its important role in developing connections between the Gulf and Atlantic waters and its relationship to the complex evolution of the Caribbean plate. Current understanding of EGoM evolution is limited primarily by publicly available data, but as the region opens to petroleum drilling and with the arrival of the EarthScope network to the region in the coming years, the need for a robust basin evolution model is pressing. Pangea rifted apart during Triassic to mid Jurassic time, and the pre-rift and syn-rift basement architecture influenced depositional patterns within the basin, including distribution of the Louann Salt. Deformation related to the opening of the EGoM was followed primarily by salt tectonic deformation during mid Jurassic to Cretaceous time, which deformed overlying strata and influenced sediment transport pathways and sediment distribution patterns. Presently, temporal and spatial relationships, if any, between halokineses and basin evolution are poorly understood. Because mass was not conserved along any given plane due to salt volume loss, multiple solutions for subsidence mechanisms, structural development, the thermal evolution of potential source rocks and development of depocenters are possible from the stratigraphic record. However, previous studies of the EGoM indicate that the earliest halokinetic deformation was triggered by the deposition of Smackover Formation carbonates above localized Norphlet Formation siliciclastics and Louann Salt. Thus, the thickness and extent of Norphlet Formation strata can be used as a reference datum in order to determine the mid Jurassic configuration and kinematics of basement-involved structures. Understanding both pre-rift and syn-rift basement structures, and mapping the distribution of syn-rift deposits provides an approach to developing a comprehensive basement model. The results can then be used to evaluate later modification, enhancement or reactivation of these basement-involved structures as the loci for salt tectonic structures. Evaluating basement-dominated and salt-dominated structural evolution in this way will advance efforts to model the EGoM evolution.