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

Abstract The late Jurassic Campeche salt basin in the southern Gulf of Mexico (GOM) forms a passive margin foldbelt in the 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 reflecting the salt thickness 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 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 the salt flow direction of the passive margin foldbelt.