Early Marine Isotope Stage 5 sea levels, coastal dune palaeoenvironments, and human occupation on the southeast coast of South Africa

摘要

Quaternary-age human and animal footprints have been reported from coastal deposits along the South African coast. These footprints and their sedimentary contexts can inform on Quaternary palaeoenvironments and processes stratigraphically associated with the palaeoanthropological record of past human occupation in the coastal zone, and exploitation of its resources. This study examines the palaeoenvironmental context and sedimentology of Marine Isotope Stage 5 aeolianite at Nahoon Point, southeastern coast of South Africa, where preserved human footprints have been previously recorded. This study identifies seven sedimentary facies from 20 logged profiles through the coastal aeolianite in order to develop a landscape-scale stratigraphic framework for coastal palaeoenvironmental reconstruction during the period of the MIS 5 highstand. Two phases of aeolianite deposition are identified, which bracket a single stepped sea-level transgression phase up to +7.82 +/- 0.82 m asl, evidenced by intraformational beachrock facies and marine benches. This correlates with the second known global MIS 5e highstand; no evidence for the first highstand reported from the literature was found in the study area. Aeolianite bed geometries and sedimentary structures indicate that wind regimes and rainfall seasonality were similar to present. Newly discovered faunal tracks in aeolianites of the first depositional phase suggest the presence of unidentified bovids of varying sizes. Evidence for human activity is preserved in all three recorded depositional phases, suggesting people were present throughout the early MIS 5 sequence despite changing environmental conditions. This evidence suggests that human occupation of coastal areas, and the exploitation of marine food resources was more widespread than generally thought in southern Africa during early MIS 5. (C) 2020 Elsevier Ltd. All rights reserved.