Seismic stratigraphy, stacking patterns and intra-clinothem architecture of a Late Holocene, Mud Wedge (Mediterranean Sea)

Holocene inner shelf mud wedges are important paleoenvironmental archives because they typically contain continuous and extensive sedimentary sequences that can document past changes in sedimentary processes at very high temporal resolution. Here we investigate the fine-scale, seismic patterns of the Late Holocene Adriatic Mud Wedge (AMW), along the western Adriatic margin, to understand the processes of river-sea interactions and their effects on sediments distribution. While analyzing high-resolution seismic reflection profiles, we documented variations in the architectural stratal stacking patterns of the AMW, largely related to short-term fluctuations in sediment supply during the last sea level high (ca. 6000 years BP). Analysis of high-resolution seismic profiles revealed that the AMW consists of five clinothems (referred to here as “seismic units” SU1 to SU5) that were roughly dated by calibration with the continuous recovery well PRAD2-4. Each seismic unit is bounded by minor floodplains (H1 to H5), reflecting periods of relative sediment starvation at the margin. Our analysis provides an interpretative tool to differentiate the fluvial contribution of marine remodeling processes during the AMW evolution on millennium to centennial timescales. In addition, small-scale geomorphic features such as erosion surfaces, small distributary channels and terminal lobes were identified to provide information on heterogeneities that may impact an unconventional fine-grained delta reservoir, both in terms of continuity and overall hydrocarbon potential.