Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean

Xavier Boës, Sandrine Prat, Vincent Arrighi, Craig Feibel, Bereket Haileab, Jason Lewis, Sonia Harmand

Research output: Contribution to journalArticle

Abstract

In the East African Rift, the western margin of Lake Turkana (northern Kenya) exposes Mio-Plio-Pleistocene lake sediments with dated volcanic horizons constraining basin dynamics at the astronomical time scale. Since the late Pliocene, coastal archaeological sites have formed within the lacustrine dynamics. Here, lake levels are reconstructed from 2.4 to 1.7 Ma using sedimentary facies and water/depth-controlled sediment association. The lacustrine stratigraphy is measured with a total station, and cyclostratigraphy is derived from tephrochronology. The water depths are evaluated from paleochemical properties of lake sediments analyzed by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry. Our reconstruction highlights that Lake Turkana rose during 100 ka insolation/eccentricity maxima periods in response to higher monsoonal inputs of the Omo River. However, Lake Turkana also expanded through an insolation minimum at 2.17-1.95 Ma. This asynchronous lake phase coincides with volcanic closure of the Omo River and Lake Turkana outflow sill to the east and the Indian Ocean. An archaeological hiatus occurs during this endorheic lake phase, and alkalinity increases at the beginning of the hiatus. The lake rose again during insolation/eccentricity maxima at 1.9-1.7 Ma, and a new outflow sill opened to the west and the Nile basin. Hominin coastal occupations return during this exorheic/freshwater lake phase.

Original languageEnglish (US)
Pages (from-to)691-704
Number of pages14
JournalQuaternary Research (United States)
Volume91
Issue number2
DOIs
StatePublished - Mar 1 2019

Fingerprint

lake level
occupation
outflow
lake
basin
river
insolation
hiatus
eccentricity
sill
lacustrine deposit
water depth
cyclostratigraphy
tephrochronology
plasma
Indian Ocean
Closure
alkalinity
spectrometry
Pliocene

All Science Journal Classification (ASJC) codes

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

Keywords

  • Early Pleistocene
  • Lake Turkana
  • Nachukui Formation
  • Omo Group deposits
  • West Turkana
  • eccentricity
  • hominin evolution
  • paleolakes

Cite this

Boës, Xavier ; Prat, Sandrine ; Arrighi, Vincent ; Feibel, Craig ; Haileab, Bereket ; Lewis, Jason ; Harmand, Sonia. / Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean. In: Quaternary Research (United States). 2019 ; Vol. 91, No. 2. pp. 691-704.
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Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean. / Boës, Xavier; Prat, Sandrine; Arrighi, Vincent; Feibel, Craig; Haileab, Bereket; Lewis, Jason; Harmand, Sonia.

In: Quaternary Research (United States), Vol. 91, No. 2, 01.03.2019, p. 691-704.

Research output: Contribution to journalArticle

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T1 - Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean

AU - Boës, Xavier

AU - Prat, Sandrine

AU - Arrighi, Vincent

AU - Feibel, Craig

AU - Haileab, Bereket

AU - Lewis, Jason

AU - Harmand, Sonia

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