New Discovery of Oligocene Strata in the Topernawi Formation, Turkana County, Kenya

Francis J. Sousa; Stephen E. Cox; Sidney R. Hemming; E. Troy Rasbury; Elena Steponaitis; Kevin Hatton; Mae Saslaw; Gregory Henkes; Patricia Princehouse; Natasha S. Vitek; Isaiah Nengo

doi:10.3389/feart.2022.799097

Frontiers in Earth Science (Feb 2022)

New Discovery of Oligocene Strata in the Topernawi Formation, Turkana County, Kenya

Francis J. Sousa,
Stephen E. Cox,
Sidney R. Hemming,
E. Troy Rasbury,
Elena Steponaitis,
Kevin Hatton,
Mae Saslaw,
Gregory Henkes,
Patricia Princehouse,
Natasha S. Vitek,
Isaiah Nengo

Affiliations

Francis J. Sousa: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
Stephen E. Cox: Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
Sidney R. Hemming: Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
E. Troy Rasbury: Department of Geosciences, Stony Brook University, Stony Brook, NY, United States
Elena Steponaitis: Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA, United States
Kevin Hatton: Department of Geosciences, Stony Brook University, Stony Brook, NY, United States
Mae Saslaw: Department of Geosciences, Stony Brook University, Stony Brook, NY, United States
Gregory Henkes: Department of Geosciences, Stony Brook University, Stony Brook, NY, United States
Patricia Princehouse: Institute for the Science of Origins, Case Western Reserve University, Cleveland, OH, United States
Natasha S. Vitek: Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, United States
Isaiah Nengo: Turkana Basin Institute, Stony Brook University, Stony Brook, NY, United States

DOI: https://doi.org/10.3389/feart.2022.799097
Journal volume & issue: Vol. 10

Abstract

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New field observations and 40Ar/39Ar geochronology reveal that the Topernawi Formation of the Ekitale Basin, northern Turkana Depression, Turkana County, Kenya was deposited entirely during the Oligocene between 29.7 ± 0.5 Ma and 29.24 ± 0.08 Ma. These bracketing ages are determined via new 40Ar/39Ar geochronology on a basaltic lava flow at the base of the section and a felsic ignimbrite near the top. A newly discovered basal unit and interbedded lava flow result in a new total sedimentary thickness of 92 m. The Topernawi Formation is the oldest dated syn-rift sedimentary section in the northern Turkana Depression.

Published in Frontiers in Earth Science

ISSN: 2296-6463 (Online)
Publisher: Frontiers Media S.A.
Country of publisher: Switzerland
LCC subjects: Science
Website: https://www.frontiersin.org/journals/earth-science

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