Brief Communication: Beyond the South African cave paradigm—Australopithecus africanus from Plio–Pleistocene paleosol deposits at Taung

Authors

  • Philip J. Hopley,

    Corresponding author
    1. Department of Earth Sciences, University College London, London, UK
    • Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK
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  • Andy I.R. Herries,

    1. Department of Archaeology, Environment and Community Planning, Australian Archaeomagnetism Laboratory, Faculty of Humanities and Social Sciences, La Trobe University, Melbourne, Australia
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  • Stephanie Edwards Baker,

    1. Institute of Human Evolution, University of the Witwatersrand, South Africa
    2. School of Geosciences, University of the Witwatersrand, South Africa
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  • Brian F. Kuhn,

    1. Institute of Human Evolution, University of the Witwatersrand, South Africa
    2. School of Geosciences, University of the Witwatersrand, South Africa
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  • Colin G. Menter

    1. Centre for Anthropological Research, University of Johannesburg, South Africa
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Correspondence to: Philip Hopley, Department of Earth and Planetary Sciences, Birkbeck, University of London, London WC1E 7HX, UK. E-mail: p.hopley@bbk.ac.uk

ABSTRACT

Following the discovery of the “Taung Child” (Australopithecus africanus) in 1924 in the Buxton-Norlim Limeworks near Taung, the fossil-bearing deposits associated with the Dart and Hrdlička pinnacles have been interpreted as the mined remnants of cave sediments that formed within the Plio–Pleistocene Thabaseek Tufa: either as a younger cave-fill or as contemporaneous carapace caves. When combined with the Plio–Pleistocene dolomitic cave deposits from the “Cradle of Humankind,” a rather restricted view emerges that South African early hominins derived from cave deposits, whereas those of east and central Africa are derived from fluvio-lacustrine and paleosol deposits. We undertook a sedimentological and paleomagnetic analysis of the pink-colored deposit (PCS) from which the “Taung Child” is purported to have derived and demonstrate that it is a calcrete, a carbonate-rich pedogenic sediment, which formed on the paleo-land surface. The deposit extends 100 s of meters laterally beyond the Dart and Hrdlička Pinnacles where it is interbedded with the Thabaseek Tufa, indicating multiple episodes of calcrete development and tufa growth. The presence of in situ rhizoconcretions and insect trace fossils (Celliforma sp. and Coprinisphaera sp.) and the distinctive carbonate microfabric confirm that the pink deposit is a pedogenic calcrete, not a calcified cave sediment. Paleomagnetic and stratigraphic evidence indicates that a second, reversed polarity, fossil-bearing deposit (YRSS) is a younger fissure-fill formed within a solutional cavity of the normal polarity tufa and pink calcrete (PCS). These observations have implications for the dating, environment, and taphonomy of the site, and increase the likelihood of future fossil discoveries within the Buxton-Norlim Limeworks. Am J Phys Anthropol 151:316–324, 2013. © 2013 Wiley Periodicals, Inc.

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