Tectonostratigraphic Evolution Of A Suprasalt Minibasin, Oligocene - Miocene Western Slope Of The Gulf Of Mexico

The petroleum industry has focused Gulf of Mexico exploration efforts on salt-related geologic provinces in search of major hydrocarbon accumulations. This work has led to recognition of the influence that salt tectonics has had on play elements of the petroleum system in the producing salt basins. In particular, the complex depositional patterns of the reservoir rocks controlled by shifting depocenters resulting from the accommodation space generated by salt withdrawal from minibasins. The focus of this research is to understand the structural and stratigraphic components that controlled the evolution of an Oligocene - Miocene suprasalt minibasin located in the upper continental slope of the western Gulf of Mexico. A methodology based on sequence stratigraphic, and structural restoration concepts was used to delineate the influence of these elements. Thus, this research will provide a more predictive model for further exploration of upper slope salt-hosted minibasins in the western Gulf of Mexico. The study area contains three depositional sequences (Sequence 1, Sequence 2, and Sequence 3) consisting of fine to very fine-grained deep-water turbidites. These sequences were stratigraphically controlled by different rates of accommodation space creation and sedimentation. The depositional sequences are dominated by low stand system tract deposition in the lower parts, and minor transgressive and / or high stand system tract deposition in the upper parts. The studied suprasalt minibasin developed in four evolutionary phases: (1) prethrusting stage, in which the stratal thickness was relatively isopachous, (2) shortening stage, in which the sediments were preferentially confined to synclines between compressional thrusts, (3) compressional folding stage, in which the underlying ductile material (salt or shale) is inflated and the overlying minibasin thin margins are folded, (4) gravitational subsidence stage, in which the minibasin fill is thick and dense enough to gravitationally sink. The minibasin became elongate to the northeast - southwest, perpendicular to the northwest - southeast regional depositional trend, which was sourced from the Rio Bravo, Rio Grande and Guadalupe rivers