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

Helen M. Roberts, Christopher Bronk Ramsey, Melissa S. Chapot, Alan L. Deino, Christine S. Lane, Céline Vidal, Asfawossen Asrat, Andrew Cohen, Verena Foerster, Henry F. Lamb, Frank Schäbitz, Martin H. Trauth, Finn A. Viehberg

Research output: Contribution to journalArticlepeer-review

Abstract

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 ∼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.

Original languageEnglish (US)
Article number107025
JournalQuaternary Science Reviews
Volume266
DOIs
StatePublished - Aug 15 2021

Keywords

  • Ar/Ar dating
  • Ethiopia
  • Geochronology
  • Optically stimulated luminescence
  • OSL
  • Quartz
  • Quaternary
  • Radiocarbon
  • SCTF
  • Tephrochronology

ASJC Scopus subject areas

  • Global and Planetary Change
  • Ecology, Evolution, Behavior and Systematics
  • Archaeology
  • Archaeology
  • Geology

Fingerprint

Dive into the research topics of 'Using multiple chronometers to establish a long, directly-dated lacustrine record: Constraining >600,000 years of environmental change at Chew Bahir, Ethiopia'. Together they form a unique fingerprint.

Cite this