Drowned carbonate‐rimmed margin controlling shelf‐edge delta progradation and sedimentation dynamics: Upper Cretaceous Woodbine Formation, Texas, USA

ABSTRACT Shelf‐edge deltas are commonly interpreted to record basinward facies migration across uninterrupted, gently dipping shelf margins; however, examples from mixed siliciclastic‐carbonate margins reveal more complex depositional dynamics. Periods and areas of carbonate sedimentation within mixed siliciclastic‐carbonate margins can modify shelf morphology by producing irregularities that persist as positive seafloor bathymetric features, even long after the cessation of the carbonate factory. Despite the widespread documentation of shelf‐edge deltas advancing across carbonate‐modified shelves, the role of carbonate‐related bathymetric relief in modulating siliciclastic sediment transport and controlling the stratigraphic architecture and facies partitioning of younger shelf‐edge deltas remains insufficiently documented. Subsurface cores, two‐dimensional (2D) seismic and wireline log data from the East Texas Basin and its adjoining northern Gulf of Mexico (GOM) margin demonstrate that the bathymetric relief of the Albian Stuart City reef exerted a primary control on the Cenomanian Woodbine shelf‐edge delta system. Beyond controlling thickness variations, the inherited bathymetry of the Stuart City reef margin continued to play a major role in routing and redirecting the overlying Woodbine deltas into the GOM deepwater and in acting as a locus for sediment instability and gravity‐flow initiation. Core‐based observations further suggest that the subdued but persistent bathymetric irregularity and relief of the Stuart City margin may have dampened wave action, amplified tidal currents and hence sustained river hyperpycnal sedimentation in areas landward of the paleo‐reef margin during the progradation of the Woodbine deltas. By integrating core‐calibrated sedimentological observations with seismic and wireline log data, this study develops a sedimentological and stratigraphic synthesis of shelf‐edge delta evolution and sediment dispersal across a drowned carbonate‐rimmed margin, positioning the Woodbine deltas of East Texas as a potential process‐based analogue for other shelf‐edge deltas that advanced over drowned rimmed margins.