Footprints of palaeocurrents in sedimentary sequences of the Cenozoic across the Maurice Ewing Bank

High-resolution seismic reflection data across the Maurice Ewing Bank, the easternmost section of the Falkland/ Malvinas Plateau in the SW South Atlantic, is integrated with information from Deep Sea Drilling Project Leg 36, Sites 327, 329, and 330 and Leg 71 Site 511. Five seismic units were identified ranging in age from the middle Jurassic to Quaternary and are interpreted with respect to the evolution of the oceanic circulation in the Atlantic sector of the Southern Ocean in response to tectonic and climatic events. Sedimentary sequences of late Cretaceous and early Paleogene include little and restricted evidence of current activity, attributable to shallow/ intermediate-depth connections between the developing South Atlantic and the Southern Ocean. In contrast, sedimentary sequences of the late Eocene/Oligocene and Neogene reveal a history of strong current-related erosion and deposition. These features are identified in specific water-depth ranges and interpreted to document proto-Upper and -Lower Circumpolar Deep Waters to have shaped the bank since the Oligocene. The Maurice Ewing Bank bathymetric high thus has been acting as a barrier for the deep and bottom water masses flowing within the Antarctic Circumpolar Current since its establishment at the Eocene-Oligocene boundary. This study provides evidence for a multi-layered ocean already in the Paleocene/early Eocene