High latitude Eocene climate deterioration: evidence from the northern Antarctic Peninsula

Clay mineral, sedimentological and geochemical data show that the northern Antarctic Peninsula (Seymour Island, La Meseta Formation) experienced a climatic deterioration from very warm, non-seasonally wet conditions at the end of the Palaeogene global optimum (early Middle Eocene ∼47 Ma) to a latest Eocene (post ∼34 Ma) regime that was cold, frost-prone and relatively dry. During the middle Middle Eocene there was an episode of strongly seasonal wet conditions, after which the climate was generally cool and humid. Overall, Eocene climatic trends in the Antarctic Peninsula mirror those recorded at ODP sites in the Southern Ocean. There is no evidence for glacial deposition on Seymour Island during either the latest Eocene (Submeseta) or the short Early Palaeocene (Sobral) cold episodes. Local Eocene climatic changes were registered by alterations in depositional and sedimentary characters of the La Meseta Formation, and reflect regional southern high latitude Palaeogene climatic mileu modulated by local tectonic events.