6-7 WTK13: ENVIRONMENTAL CONTEXT FOR HOMININ EVOLUTION IN THE TURKANA BASIN OF KENYA

Session: Integrating 20 Years of Scientific Drilling in the East African-Syrian Rift: A Session In Honor of Andrew Cohen, Part I

Presenting Author:

Craig Feibel

Authors:

Feibel, Craig S.¹, Beck, Catherine C.², Billingsley, Anne³, Campisano, Christopher J.⁴, Lupien, Rachel⁵, Rabideaux, Nathan⁶, Rucina, Stephen⁷, Sier, Mark⁸, Stone, Jeffery Robert⁹, Yost, Chad L.¹⁰, Cohen, Andrew S.¹¹

(1) Earth and Planetary Sciences, Rutgers University, Piscataway, NJ, USA, (2) Hamilton College, CLINTON, NY, USA, (3) University of Arizona, Tucson, AZ, USA, (4) Arizona State University, Tempe, AZ, USA, (5) Aarhus University, Aarhus, Denmark, (6) Rutgers University, Newark, NJ, USA, (7) National Museums of Kenya, Nairobi, Kenya, (8) CENIEH, Burgos, Spain, (9) Indiana State University, Terre Haute, IN, USA, (10) Indiana State University, Terre Haute, IN, USA, (11) University of Arizona, Tucson, AZ, USA,

Abstract:

The Hominin Sites and Paleolakes Drilling Project (HSPDP), led by Andy Cohen, collected the WTK13 core from the western Turkana Basin in order to develop a high-resolution environmental context in the midst of one of the most prolific paleoanthropological records known from eastern Africa.  The 215 m long core spans the critical time interval from 1.9 – 1.4 Ma, bridging significant gaps between the paleontological and archaeological records of the basin and the extensive outcrops that have traditionally established context for them. Leveraging the high-resolution world of sedimentological, geochemical, and biological proxies, the record elucidates mechanisms driving climate, tectonics, and ecological change.  The core perspective provides a sharp contrast to comparable outcrop records, lacking clear macrotephra markers while preserving diagenetically sensitive components like pyrite and pollen.  The expected facies-constant deep lake muds instead demonstrated a rich high-frequency record of exposure and pedogenesis amidst typical lacustrine signals.  Preservation biases limit continuity of some proxies, such as phytoliths and diatoms, but where unaltered, they display remarkably detailed preservation. Biomarker evidence suggests long-term stability in mean hydroclimate paced by strong precessional periodicity and variable responses to changing climatic forcing.  The WTK13 core has produced a detailed and complex archive of environmental variability in direct association with the Turkana Basin hominin record.  Key finds, such as the Turkana Boy skeleton (KNM-WT 15000) and early Acheulean technology, can be tightly placed within this context.  Continued study of this core record and expansion of core perspectives within the Turkana Basin will further elaborate crucial aspects of the environmental backdrop for the study of human origins as intended in the conception of the HSPDP.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8675

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