Middle Stone Age Ochre Processing and Behavioural Complexity in the Horn of Africa: Evidence from Porc-Epic Cave, Dire Dawa, Ethiopia

PLoS One. 2016 Nov 2;11(11):e0164793. doi: 10.1371/journal.pone.0164793. eCollection 2016.

Abstract

Ochre is a common feature at Middle Stone Age (MSA) sites and has often been interpreted as a proxy for the origin of modern behaviour. However, few ochre processing tools, ochre containers, and ochre-stained artefacts from MSA contexts have been studied in detail within a theoretical framework aimed at inferring the technical steps involved in the acquisition, production and use of these artefacts. Here we analyse 21 ochre processing tools, i.e. upper and lower grindstones, and two ochre-stained artefacts from the MSA layers of Porc-Epic Cave, Dire Dawa, Ethiopia, dated to ca. 40 cal kyr BP. These tools, and a large proportion of the 4213 ochre fragments found at the site, were concentrated in an area devoted to ochre processing. Lower grindstones are made of a variety of raw materials, some of which are not locally available. Traces of use indicate that different techniques were employed to process ochre. Optical microscopy, XRD, μ-Raman spectroscopy, and SEM-EDS analyses of residues preserved on worn areas of artefacts show that different types of ferruginous rocks were processed in order to produce ochre powder of different coarseness and shades. A round stone bearing no traces of having been used to process ochre is half covered with residues as if it had been dipped in a liquid ochered medium to paint the object or to use it as a stamp to apply pigment to a soft material. We argue that the ochre reduction sequences identified at Porc-Epic Cave reflect a high degree of behavioural complexity, and represent ochre use, which was probably devoted to a variety of functions.

Publication types

  • Historical Article

MeSH terms

  • Anthropology, Cultural
  • Anthropology, Physical
  • Caves*
  • Ethiopia
  • Geography
  • History, Ancient
  • Humans
  • Social Behavior*

Grants and funding

Research by DR was funded by the Generalitat de Catalunya (Ajuts per a la contractació de personal investigador novell, FI-DGR), the Doctoral Research scholarship Programme of the Martine Aublet Foundation, and the Eiffel Excellence Scholarship Programme of the French Ministry of Foreign Affairs and International Development. Research by AP was funded by the Generalitat de Catalunya (Beatriu de Pinós postdoctoral fellowship, 2014 BP-A 00122). This research was conducted with the financial support of the Wenner-Gren Foundation (Gr. 8786), the LaScArBx research programme, supported by the ANR ANR-10-LABX-52, and the European Research Council Advanced Grant, TRACSYMBOLS No. 249587 awarded under the FP7 program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.