Palaeomagnetic and synchrotron analysis of >1.95 Ma fossil-bearing palaeokarst at Haasgat, South Africa

Authors

  • Andy I.R. Herries Australian Archaeomagnetism Laboratory, Archaeology, Environment and Community Planning, La Trobe University, Melbourne, Australia
  • Peter Kappen 1. Physics, La Trobe University, Melbourne, Australia 2. Australian Synchrotron, X-ray Fluorescence Microprobe Beamline, Melbourne, Australia
  • Anthony D.T. Kegley Biomedical Sciences, Grand Valley State University, Allendale, MI, USA
  • David Patterson Australian Synchrotron, X-ray Fluorescence Microprobe Beamline, Melbourne, Australia
  • Daryl L. Howard Australian Synchrotron, X-ray Fluorescence Microprobe Beamline, Melbourne, Australia
  • Martin D. de Jonge Australian Synchrotron, X-ray Fluorescence Microprobe Beamline, Melbourne, Australia
  • Stephany Potze Plio-Pleistocene Palaeontology Section, Ditsong National Museum of Natural History, Pretoria, South Africa
  • Justin W. Adams Anatomy and Developmental Biology, Monash University, Melbourne, Australia

DOI:

https://doi.org/10.1590/sajs.2014/20130102

Keywords:

biochronology, X-ray flourescence, synchrotron radiation;, iron, primate fossils, magnetostratigraphy

Abstract

Palaeomagnetic analysis indicates that Haasgat, a fossil-bearing palaeocave in the Gauteng Province of South Africa, is dominated by reversed magnetic polarity in its oldest, deepest layers and normal polarity in the younger layers. The presence of in-situ Equus specimens suggests an age of less than ~2.3 Ma, while morphological analysis of faunal specimens from the ex-situ assemblage suggests an age greater than 1.8 Ma. Given this faunal age constraint, the older reversed polarity sections most likely date to the beginning of the Matuyama Chron (2.58–1.95 Ma), while the younger normal polarity deposits likely date to the very beginning of the Olduvai Sub-Chron (1.95–1.78 Ma). The occurrence of a magnetic reversal from reversed to normal polarity recorded in the sequence indicates the deposits of the Bridge Section date to ~1.95 Ma. All the in-situ fossil deposits that have been noted are older than the 1.95 Ma reversal, but younger than 2.3 Ma. Haasgat therefore dates to an interesting time period in South African human evolution that saw the last occurrence of two australopith species at ~2.05–2.02 Ma (Sts5 Australopithecus africanus from Sterkfontein Member 4) to ~1.98 Ma ( Australopithecus sediba from Malapa) and the first occurrence of early Homo (Sk847), Paranthropus and the Oldowan within Swartkrans Member 1 between ~2.0 Ma and ~1.8 Ma.

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Published

2014-03-27

How to Cite

1.
Herries AI, Kappen P, Kegley AD, Patterson D, Howard DL, de Jonge MD, Potze S, Adams JW. Palaeomagnetic and synchrotron analysis of >1.95 Ma fossil-bearing palaeokarst at Haasgat, South Africa. S. Afr. J. Sci. [Internet]. 2014 Mar. 27 [cited 2021 Sep. 23];110(3/4):1-12. Available from: https://sajs.co.za/article/view/3741