Structural styles and evolution of the Campeche salt basin, southern Gulf of Mexico

The late Jurassic Campeche salt basin in the southern Gulf of Mexico (GOM) forms a passive margin foldbelt of late Middle Miocene to the Recent age. The Campeche salt basin is defined by a 200-km-wide updip zone of listric, normal faults of the Comalcalco and Macuspana rifts, and a coeval, 300-km-wide, downdip zone of deeper-water, salt-cored folds, detachment folds with kink bands, thrusts, and diapirs. This study integrates shipborne magnetic data with 28,612 km of pre-stack, depth-migrated, 2D seismic data to reconstruct the geometry of the top of the Paleozoic basement and base-salt topography above which the passive margin foldbelt evolved. Magnetic and basement mapping reveals that the 40-55-km-wide Campeche segment of the 400 km long GOM outer marginal trough marks the limit of the northwest-directed passive margin foldbelt. The elongated basement depression of the outer marginal trough combined with a basement step-up fault along the edge of Jurassic oceanic crust localizes the thickest Bajocian-early Callovian salt. The outer marginal trough controls the arcuate, northwestward, and downdip path of salt flowage within the passive margin foldbelt. •The Campeche salt basin in the southern Gulf of Mexico forms a late Middle Miocene to Recent passive margin foldbelt.•Mapping of the top Paleozoic basement reveals an overall northwestward dip that reflects the base-salt topography.•A 40-55-km-wide, late Jurassic rift forms an elongate structural low that concentrates gravity-driven structures.•Updip extension in the Comalcalco and Macuspana rifts results in a 300-km-wide zone of downdip shortening.