@article{c02329c9fb3b480bad1f7c0a5bbe9d2f,
title = "Integrative geochronology calibrates the Middle and Late Stone Ages of Ethiopia{\textquoteright}s Afar Rift",
abstract = "The Halibee member of the Upper Dawaitoli Formation of Ethiopia{\textquoteright}s Middle Awash study area features a wealth of Middle and Later Stone Age (MSA and LSA) paleoanthropological resources in a succession of Pleistocene sediments. We introduce these artifacts and fossils, and determine their chronostratigraphic placement via a combination of established radioisotopic methods and a recently developed dating method applied to ostrich eggshell (OES). We apply the recently developed 230Th/U burial dating of OES to bridge the temporal gap between radiocarbon (14C) and 40Ar/39Ar ages for the MSA and provide 14C ages to constrain the younger LSA archaeology and fauna to ∼24 to 21.4 ka. Paired 14C and 230Th/U burial ages of OES agree at ∼31 ka for an older LSA locality, validating the newer method, and in turn supporting its application to stratigraphically underlying MSA occurrences previously constrained only by a maximum 40Ar/39Ar age. Associated fauna, flora, and Homo sapiens fossils are thereby now fixed between 106 ± 20 ka and 96.4 ± 1.6 ka (all errors 2σ). Additional 40Ar/39 results on an underlying tuff refine its age to 158.1 ± 11.0 ka, providing a more precise minimum age for MSA lithic artifacts, fauna, and H. sapiens fossils recovered ∼9 m below it. These results demonstrate how chronological control can be obtained in tectonically active and stratigraphically complex settings to precisely calibrate crucial evidence of technological, environmental, and evolutionary changes during the African Middle and Late Pleistocene.",
keywords = "Ethiopia, Geochronology, Late stone age, Middle awash, Middle stone age",
author = "Niespolo, {Elizabeth M.} and Giday WoldeGabriel and Hart, {William K.} and Renne, {Paul R.} and Sharp, {Warren D.} and Shackley, {M. Steven} and Ambrose, {Stanley H.} and Berhane Asfaw and Yonas Beyene and Brasil, {Marianne F.} and Carlson, {Joshua P.} and Yonatan Sahle and White, {Tim D.}",
note = "Funding Information: Professorship at Miami University (2010-15); M.F.B. acknowledges support from the University of California, Berkeley Chancellor{\textquoteright}s Fellowship and University of California, Berkeley Portuguese Studies Program; Y.S. and Y.B. acknowledge support from the L.S.B. Leakey Foundation and the Paleontological Scientific Trust for archaeological fieldwork and laboratory analyses, including obsidian geochemistry. Any opinions, findings, and conclusions expressed in this study are those of the authors and do not necessarily reflect the views of the granting agencies or institutions named above. Funding Information: Foundation is gratefully acknowledged. This work was further supported in part by the Institute of Geophysics and Planetary Physics of the Los Alamos National Laboratory, Digital Globe, the Japan Society for the Promotion of Science, and donors to the Human Evolution Research Center. E.M.N. and W.D.S. were supported by NSF Grant BCS-1727085 to W.D.S. and C.A. Tryon and by the Ann and Gordon Getty Foundation, with thanks to Christina Polito-Halter and Brian Jones for help with 230Th/U analyses and Luis-Erick Aguirre Palafox and Chihiro Ishida for geochronological sample preparation assistance. W.K.H. acknowledges support from the Janet and Elliot Baines Publisher Copyright: {\textcopyright} 2021 National Academy of Sciences. All rights reserved.",
year = "2021",
month = dec,
day = "14",
doi = "10.1073/pnas.2116329118",
language = "English (US)",
volume = "118",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "50",
}