EGU23-10195, updated on 26 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Last Interglacial Saharo-Arabian palaeoclimate variability and Homo sapiens dispersal: insights from the speleothem record of Southern Arabia

Samuel Nicholson1,2, Matthew Jacobson3, Huw Groucutt4,5, Monika Markowska2, Hubert Vonhof2, Rob Hosfield6, Alistair Pike7, Stephen Burns8, Albert Matter9, and Dominik Fleitmann10
Samuel Nicholson et al.
  • 1Ecology and Evolutionary Biology, University of Reading, Reading, United Kingdom
  • 2Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany
  • 3Division of Agrarian History, Swedish University of Agricultural Sciences, Uppsala, Sweden
  • 4Department of Classics and Archaeology, University of Malta, Msida, Malta
  • 5Extreme Events Research Group, Max Planck Institutes for Geoanthropology, Chemical Ecology, and Biogeochemistry, Jena, Germany
  • 6School of Archaeology, Geography and Environmental Sciences, University of Reading, Reading, United Kingdom
  • 7Department of Archaeology, University of Southampton, Southampton, United Kingdom
  • 8Department of Geosciences, University of Massachusetts, Massachusetts, United States of America
  • 9Institute of Geophysics, University of Bern, Bern, Switzerland
  • 10Department of Environmental Sciences, University of Basel, Basel, Switzerland

The fluctuating climatic conditions of the Saharo-Arabian desert belt are increasingly important for both palaeoclimatic and palaeoanthropological debates. Currently, Saharo-Arabia acts as a vast biogeographic barrier between the Afrotropical and Palaearctic realms. On orbital timescales, northward incursions of the African (ASM) and Indian (ISM) Summer Monsoons activated fluvio-lacustrine systems and led to the formation of grassland habitats. The formation of these habitats has been considered a crucial factor in Homo sapiens dispersals into the Saharo-Arabian deserts and beyond. The so-called “northern route” favours a terrestrial dispersal through green palaeohydrological corridors. However, a maritime “southern route” during the sea-level low-stand of Glacial Termination-II (T-II) has also been proposed. The precise phasing between the onset of wetter conditions and rising sea-levels may thus be a crucial factor for testing these alternative hypotheses. Here, we present a precisely dated high-resolution (<100 yrs) stalagmite record from Mukalla Cave, Yemen, at a key location on the “southern route”. Wetter conditions in Southern Arabia prevailed from ~127.7 to ~121.1 ka BP and occurred when sea-levels were already higher than at present, revealing a phase-lag of several thousand-years between sea-level rise and the onset of pluvial conditions. This lag is likely related to the colder conditions of Heinrich Stadial-11, which supressed the interhemispheric pressure gradient and the ASM and ISM throughout T-II despite rising insolation. δ18Oca values indicate rainfall intensity during the ~127.7 to ~121.1 ka BP interval 1) followed low-latitude insolation, and 2) was the greatest in the last 130,000 years.  Additionally, a mixed C3/C4 grassland environment, as revealed by stalagmite δ13Cca values, was present in the now desert interior of Yemen. Combined with archaeological evidence, we discuss the potential implications our results have for H. sapiens biogeographical shifts and dispersal processes across Saharo-Arabia during early MIS 5.


How to cite: Nicholson, S., Jacobson, M., Groucutt, H., Markowska, M., Vonhof, H., Hosfield, R., Pike, A., Burns, S., Matter, A., and Fleitmann, D.: Last Interglacial Saharo-Arabian palaeoclimate variability and Homo sapiens dispersal: insights from the speleothem record of Southern Arabia, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10195,, 2023.