Geological Society of America

T184 Human Evolution and Environmental History in Africa: 25 Years of Transformative Research (Posters)

Tuesday, 6 November 2018
9:00 AM - 6:30 PM
Halls J-K

ENVIRONMENTAL HISTORY AND HUMAN EVOLUTION IN EASTERN AFRICA: THE 550,000-YEAR CLIMATE RECORD FROM THE CHEW BAHIR BASIN, AN HSPDP KEY SITE IN SOUTHERN ETHIOPIA

Paper number: T184-6
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Verena Foerster
Institute of Geography Education, Cologne
Henry F. Lamb
Aberystwyth University, Aberystwyth
Christine S. Lane
University of Oxford, Oxford, N/A
Melanie Leng
British Geological Survey, Nottingham
Anders Noren
University of Minnesota, Minneapolis, MN
Helen Roberts
Aberystwyth University, Aberystwyth
Frank Schaebitz
Institute of Geography Education, Cologne
Martin H. Trauth
Institute of Earth and Environmental Science, Potsdam
Asfawossen Asrat
School of Earth Sciences, Addis Ababa
Andrew S. Cohen Presenting Author
University of Arizona, Tucson, AZ
Jonathan R. Dean
School of Environmental Sciences, Hull
Alan L. Deino
Berkeley Geochronology Center, Berkeley, CA
Daniel M. Deocampo
Georgia State University, Atlanta, GA
Walter Duesing
University of Potsdam, Potsdam
Christina Guenter
University of Potsdam, Potsdam
Annett Junginger
Department of Earth Sciences, Tuebingen

Abstract

As a contribution towards an enhanced understanding of human-climate interactions, the Hominin Sites and Paleolakes Drilling Project (HSPDP) has successfully cored six dominantly lacustrine archives of climate change during the last 3.3 Ma in eastern Africa. All six sites in Ethiopia and Kenya are adjacent to key paleoanthropological research areas encompassing diverse milestones in human evolution, dispersal episodes, and technological innovation. The 280 m-long Chew Bahir sediment records, recovered from a deep tectonically-bound basin in the southern Ethiopian rift in late 2014, cover the past 550 ka of environmental history, a time period that includes the transition to the Middle Stone Age, the emergence of Homo sapiensin eastern Africa and the dispersal of anatomically modern humans.

Here we present first results of the high-resolution Chew Bahir geochemical, mineralogical and sedimentological data sets for the last 550 ka. These comprise grain-size analysis, MSCL, XRF geochemistry, XRD and stable isotope data that indicate dramatic wet-dry oscillations on different time scales during this time interval. Correlating our data with other established records from e.g. Northern Africa, the Eastern Mediterranean or the Indian Ocean,highlights which role climate fluctuations could have played in opening and closing possible corridors for human migration waves.

Together with a high quality geochronology, our growing understanding of site-specific proxy formation and the establishment of climate proxies for Chew Bahir will provide a robust environmental history on decadal to orbital timescales. Based on these results we will be able to test and discuss climate related hypotheses on human evolution and dispersal.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-317247

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