Using multiple chronometers to establish a long, directly-dated lacustrine record: Constraining >600,000 years of environmental change at Chew Bahir, Ethiopia

QUATERNARY SCIENCE REVIEWS

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Article

Roberts, Helen M.¹  Ramsey, Christopher Bronk²  Chapot, Melissa S.¹  Deino, Alan L.³  Lane, Christine S.⁴  Vidal, Celine⁴  Asrat, Asfawossen^5,6  Cohen, Andrew⁷  Foerster, Verena⁸  Lamb, Henry F.^1,9  Schaebitz, Frank⁸  Trauth, Martin H.¹⁰  Viehberg, Finn A.¹¹ 

[1] Aberystwyth Univ, Dept Geog & Earth Sci, Aberystwyth SY23 3DB, Dyfed, Wales

[2] Sch Archaeol, 1 South Parks Rd, Oxford OX1 3TG, England

[3] Berkeley Geochronol Ctr, 2455 Ridge Rd, Berkeley, CA 94709 USA

[4] Univ Cambridge, Dept Geog, Cambridge CB2 3EN, England

[5] Addis Ababa Univ, Sch Earth Sci, POB 1176, Addid Ababa, Ethiopia

[6] Botswana Int Univ Sci & Technol, Dept Min & Geol Engn, Private Bag 16, Palapye, Botswana

[7] Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA

[8] Univ Cologne, Inst Geog Educ, Gronewaldstr 2, D-50931 Cologne, Germany

[9] Trinity Coll Dublin, Sch Nat Sci, Bot Dept, Dublin, Ireland

[10] Univ Potsdam, Inst Geosci, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany

[11] Univ Greifswald, Inst Geog & Geol, Friedrich Ludwig Jahn Str 16, D-17489 Greifswald, Germany

关键词: Geochronology;    Optically stimulated luminescence;    OSL;    Quartz;    Radiocarbon;    40Ar/39Ar dating;    SCTF;    Tephrochronology;    Quaternary;    Ethiopia;   

DOI  :  10.1016/j.quascirev.2021.107025

来源: Elsevier

【 摘 要 】

Despite eastern Africa being a key location in the emergence of Homo sapiens and their subsequent dispersal out of Africa, there is a paucity of long, well-dated climate records in the region to contextualize this history. To address this issue, we dated a similar to 293 m long composite sediment core from Chew Bahir, south Ethiopia, using three independent chronometers (radiocarbon, 40Ar/39Ar, and optically stimulated luminescence) combined with geochemical correlation to a known-age tephra. The site is located in a climatically sensitive region, and is close to Omo Kibish, the earliest documented Homo sapiens fossil site in eastern Africa, and to the proposed dispersal routes for H. sapiens out of Africa. The 30 ages generated by the various techniques are internally consistent, stratigraphically coherent, and span the full range of the core depth. A Bayesian age-depth model developed using these ages results in a chronology that forms one of the longest independently dated, high-resolution lacustrine sediment records from eastern Africa. The chronology illustrates that any record of environmental change preserved in the composite sediment core from Chew Bahir would span the entire timescale of modern human evolution and dispersal, encompassing the time period of the transition from Acheulean to Middle Stone Age (MSA), and subsequently to Later Stone Age (LSA) technology, making the core well-placed to address questions regarding environmental change and hominin evolutionary adaptation. The benefits to such studies of direct dating and the use of multiple independent chronometers are discussed. (C) 2021 Elsevier Ltd. All rights reserved.

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