Late Pleistocene records of speleothem stable isotopic compositions from Pinnacle Point on the South African south coast

Kerstin Braun, Miryam Bar-Matthews, Alan Matthews, Avner Ayalon, Richard M. Cowling, Panagiotis Karkanas, Erich C. Fisher, Kelsey Dyez, Tami Zilberman, Curtis Marean

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Highly resolved, well-dated paleoclimate records from the southern South African coast are needed to contextualize the evolution of the highly diverse extratropical plant communities of the Greater Cape Floristic Region (GCFR) and to assess the environmental impacts on early human hunter-gatherers. We present new speleothem stable oxygen and carbon isotope ratios (δ 18 Oc and δ 13 C) from two caves at Pinnacle Point, South Africa, covering the time between 330 and 43 ka. Composite δ 18 Oc and δ 13 C records were constructed for Staircase Cave and PP29 by combining all stable isotope analyses into a single time series and smoothing by a 3-point running mean. δ 18 Oc and δ 13 C values record changes in rainfall seasonality and the proportions of C3 and C4 plants in the vegetation, respectively. We show that in general increased summer rainfall brought about a wider spread of C4 grasses and retreat of the C3 plant-dominated GCFR communities. The occurrence of summer rainfall on the southern coast of South Africa was linked to total rainfall amounts in the interior region through tropical temperate troughs. These rainfall systems shifted the southern coastal climate toward more summer (winter) rainfall when precession was high (low) and/or the westerlies were in a northern (southern) position.

Original languageEnglish (US)
Pages (from-to)265-288
Number of pages24
JournalQuaternary Research (United States)
Volume91
Issue number1
DOIs
StatePublished - Jan 1 2019

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Keywords

  • Carbon isotopes
  • Oxygen isotopes
  • South Africa
  • Speleothem

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Earth-Surface Processes
  • Earth and Planetary Sciences(all)

Cite this

Braun, K., Bar-Matthews, M., Matthews, A., Ayalon, A., Cowling, R. M., Karkanas, P., Fisher, E. C., Dyez, K., Zilberman, T., & Marean, C. (2019). Late Pleistocene records of speleothem stable isotopic compositions from Pinnacle Point on the South African south coast. Quaternary Research (United States), 91(1), 265-288. https://doi.org/10.1017/qua.2018.61