Late glacial (17,060-13,400 cal yr BP) sedimentary and paleoenvironmental evolution of the Sekhokong Range (Drakensberg), southern Africa

PLoS One. 2021 Mar 17;16(3):e0246821. doi: 10.1371/journal.pone.0246821. eCollection 2021.

Abstract

Southern Africa sits at the junction of tropical and temperate systems, leading to the formation of seasonal precipitation zones. Understanding late Quaternary paleoclimatic change in this vulnerable region is hampered by a lack of available, reliably-dated records. Here we present a sequence from a well-stratified sedimentary infill occupying a lower slope basin which covers 17,060 to 13,400 cal yr BP with the aim to reconstruct paleoclimatic variability in the high Drakensberg during the Late Glacial. We use a combination of pollen, total organic carbon and nitrogen, δ13C, Fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR) spectral and elemental data on contiguous samples with high temporal resolution (10 to 80 years per sample). Our data support a relatively humid environment with considerable cold season precipitation during what might have been the final stage of niche-glaciation on the adjoining southern aspects around 17,000 cal yr BP. Then, after an initial warmer and drier period starting ~15,600 cal yr BP, we identify a return to colder and drier conditions with more winter precipitation starting ~14,380 cal yr BP, which represents the first local evidence for the Antarctic Cold Reversal (ACR) in this region. On decadal to centennial timescales, the Late Glacial period was one marked by considerable climatic fluctuation and bi-directional environmental change, which has not been identified in previous studies for this region. Our study shows complex changes in both moisture and thermal conditions providing a more nuanced picture of the Late Glacial for the high Drakensburg.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa, Southern
  • Biological Evolution*
  • Fossils*
  • Geologic Sediments*
  • Seasons
  • Trees

Grants and funding

MEK and MH received funding from the Bolin Centre for Climate Research, Research Area 5 for completing fieldwork and age dating. MH was granted funding from the Swedish Society for Anthropology and Geography (SSAG) for fieldwork and a research visit. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.