f Regional Source Rock Maturity Modeling along the Campeche Salt Basin, Southern Gulf of Mexico

Extending over 700 km along the southern Gulf of Mexico (GOM), the Callovian-Bajocian Campeche salt basin remains one of the least explored and drilled areas of the GOM basin. The objectives of this study include: 1) to image and structurally restore the top surface of the top of Paleozoic crystalline basement; 2) to understand the role of Paleozoic orogenic basement architecture and Triassic-Jurassic rift structures on total Mesozoic-Cenozoic sedimentary thickness; and 3) to use gravity data to determine crustal thickness and its related heat flow variations for the thermal maturity of source rocks within the basin. We integrate a grid of 23,600 line-km of 2D seismic reflection profiles with published wells and potential fields data. The potential fields data were processed to provide an improved image of the subsalt top basement surface at a depth of 6–15 km. The top basement morphology is a northward-dipping, subsalt surface in the depth range of 6–15 km. The top basement map reveals the 40–55-km-wide Campeche segment of the 670-km long GOM outer marginal trough, formed by necking of continental crust prior to the formation of late Jurassic oceanic crust. The elongate and fault-bounded basement depression of the outer marginal trough combined with the presence of "step-up fault" on its seaward edge onto more elevated Jurassic oceanic crust is imaged in high resolution using the tilt derivative of the Bouguer anomaly. We can also resolve the triangular terminus of the edge of late Jurassic oceanic crust that underlies the coastal area near San Andres Tuxtla. Mapping of 2D seismic lines reveals approximately 2–7 km of total sediment thickness along the slope of the Yucatan carbonate platform, which thickens up to 15 km along the axis of the outer marginal trough. Gravity inversion reveals an attenuated continental crustal thickness of ~10–20 km beneath the outer marginal trough and ~20–35 km beneath the less extended Yucatan block. Using this framework of crustal and sedimentary thickness, we present basin models to test hydrocarbon maturity based on Tithonian source rocks. We support our proposed areas of maturity with a compilation of direct hydrocarbon indicators from these sub-basins.