6-1 Synthesizing Two Decades of Afrosyrian Rift Science—A Tribute to Andy Cohen

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

Presenting Author:

Lisa Park Boush

Authors:

Park Boush, Lisa E.¹, Goldstein, Steven L.², McGlue, Michael M.³, Noren, Anders⁴

(1) Earth Sciences, University of Connecticut, Storrs, CT, USA, (2) LDEO, Columbia University, Palisades, NY, USA, (3) University of Kentucky Earth and Environmental Sciences, Lexington, KY, USA, (4) U. Minnesota - CSD Facility, Minneapolis, MN, USA,

Abstract:

Over the past two decades, continental scientific drilling research spanning from the East African Rift Valley into western Asia has produced transformative findings, reshaping our understanding of paleoenvironments, paleoclimatology, paleoecology, and paleoanthropology in the region. To date, these advances have largely occurred within the framework of individual drilling projects and their associated science teams. A substantial number of these projects have been completed—including those at Lake Van, the Dead Sea, the Hominin Sites and Paleolakes Drilling Project (HSPDP), Lake Challa, and Lake Malawi—with many more proposed, such as Lake Kinneret, the Danakil Basin, Chew Bahir, Lake Victoria, Lake Turkana, and Lake Tanganyika.

A central driving force behind many of these efforts was the late Andy Cohen. He played a leading role in, or contributed significantly to, major projects such as Lake Malawi and HSPDP, and provided support to numerous other past and future initiatives. While Andy’s scientific contributions were extensive, his broader vision extended beyond individual projects, aiming to synthesize drill core records from continental lakes—along with deep sea cores—spanning the ~6,000 km latitudinal and modern climatic gradient (~25°S to 38°N) of the East African–Syrian Rift, to understand how regional climates and ecosystems responded to global climate change over time.

To date, high-resolution records at continental drill sites exist at solar variability timescales (~0.001–0.5 kyr) for proxies such as XRF, gamma density, magnetic susceptibility (MS), and color reflectance. Other proxies—such as carbonate isotopes, XRD, and phytoliths—are available at millennial timescales (~0.1–5 kyr), while pollen, ostracods, leaf wax isotopes, charcoal, diatoms and radiogenic isotopes provide insight at orbital scales (~5–100 kyr). By synthesizing these diverse records, we can begin to address fundamental questions and long-standing controversies related to: 1) the influence of low- vs. high-latitude climate drivers on this region over time; 2) the role of higher-frequency events (at millennial or even shorter timescales) in driving environmental change across the rift system; 3) the ecological consequences of these climate shifts; and 4) the implications of such changes for modern human evolution and dispersal out of Africa. This was Andy Cohen’s vision—and the central theme of the GSA Topical Session held in his honor.

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

doi: 10.1130/abs/2025AM-9814

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