Bottom-current erosion along a traverse in the South Atlantic sector of the Southern Ocean

Abstract

The magnetostratigraphy and biostratigraphy of twenty-five piston cores on a profile from Antarctica to the Cape Basin south of Africa reveal disconformities in the sedimentary record which are attributed to bottom-current erosion. Increased Antarctic Bottom Water production removed all sediment in the Weddell and Cape Basins younger than middle Pliocene (2.5 m.y.) with Miocene sediment exposed at or near the seafloor at some locations. Increases in the velocity of the Circumpolar Deep Water eroded lower Pliocene to upper Pliocene (4.0–2.0 m.y.) sediment on the crest and south flank of the Atlantic-Indian Ridge and maintains an active scour zone today with middle Pleistocene (1.0 m.y.) sediment exposed at the seafloor.