Fault kinematics: A record of tectono-climatically controlled sedimentation along passive margins, an example from the U.S. Gulf of Mexico

Abstract

Abstract Faults offsetting sedimentary strata can record changes in sedimentation driven by tectonic and climatic forcing. Fault kinematic analysis is effective at evaluating changes in sediment volumes at salt/shale-bearing passive margins where sediment loading drives faulting. We explore these processes along the northern Gulf of Mexico. Incremental throw along 146 buried faults studied across onshore Louisiana revealed continual Cenozoic fault reactivation punctuated by inactive periods along a few faults. Fault scarp heights measured from light detection and ranging (LiDAR) data are interpreted to show that Cenozoic fault reactivation continued through the Pleistocene. The areas of highest fault throw and maximum sediment deposition shifted from southwest Louisiana in the early Miocene to southeast Louisiana in the middle–late Miocene. These changes in the locus of maximum fault reactivation and sediment deposition were controlled by changing tectonics and climate in the source areas. Early Miocene fault throw estimates indicate a depocenter farther east than previously mapped and support the idea that early Miocene Appalachian Mountain uplift and erosion routed sediment to southeast Louisiana. By correlating changes in fault throw with changes in sediment deposition, we suggest that (1) fault kinematic analysis can be used to evaluate missing sediment volumes because fault offsets can be preserved despite partial erosion, (2) fault throw estimates can be used to infer changes in past tectonic and climate-related processes driving sedimentation, and (3) these observations are applicable to other passive margins with mobile substrates and faulted strata within overfilled sedimentary basins.