Kinematics of regional salt flow in the northern Gulf of Mexico

The kinematics of regional-scale salt flow in the northern Gulf of Mexico is analysed using: (i) a map of shelf-break contours at the termination of successive depositional episodes; (ii) the location and geometry of large-scale structures of the slope domain as imaged by seismics; and (iii) digital slope bathymetry. In the north margin, salt has flowed towards the SW since the Cretaceous with three main stages of development prior to, during and after a massive salt extrusion in the Early Miocene time. The corresponding sequence of structural development is discussed using a laboratory model. Contrary to all previous interpretations that invoked sedimentary loading as the main driving force, the analysis of regional-scale salt flow implies that the salt tectonics of the northern Gulf of Mexico is predominantly controlled by gliding above the margin dip. The SW-directed salt flow indicates that the north margin of the northern Gulf of Mexico trends NW–SE, in agreement with plate kinematic models in which the Yucatan continental block has undergone a 45–60° dextral rotation relative to its present orientation.