Sedimentary model for mixed depositional systems along the Pacific margin of the Antarctic Peninsula: Decoding the interplay of deep-water processes

Mixed (turbidite-contourite) depositional systems are formed by a complex interplay of deep-water processes. An evaluation their morphological elements and lateral spatial distribution is crucial to better understand the transport processes, involving along-slope bottom currents down-slope turbidity currents. This work investigates extensive still active mixed developed along Pacific margin Antarctic Peninsula, which comprise large asymmetric mounded drifts, dendritic channel-complex wide trunk channels. These offer unique setting investigate diverse at high-resolution scale (10–100 m), using multibeam bathymetry acoustic sub-bottom profiles. Four main seismic units define distinct evolutionary stages for Pleistocene present day record: a) 1.3–1 Ma , characterized aggradational drifts built dominant current; b) 1–0.6 synchronous interactions between SW-flowing current NW-directed currents; c) 0.6–0.2 deposition thick gravitational deposits across under weak comprising modified Lower Circumpolar Deep Water (LCDW); d) 0.2 – when current, flow speed fluctuations, ephemeral led intercalations turbidites, contourites, reworked turbidite hemipelagites. Alternations in stratigraphic stacking pattern suggest cyclic temporal variations gravity-driven processes currents, were responsible construction these modern themselves controlled glacial-interglacial changes. The new results compared with similar decode involved formation, explore short- long-term time scales, propose conceptual sedimentary model. • Modern exist on Peninsula's margin. A model explains formation evolution systems. Synchronous asynchronous along- Lateral vertical sediment reveal controlling factors. Cyclic patterns visible profiles reflect cycles.