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

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.

Back to the Grindstone? The Archaeological Potential of Grinding-Stone Studies in Africa with Reference to Contemporary Grinding Practices in Marakwet, Northwest Kenya

“…African archaeological assemblages attest to the importance of grinding-stones for pounding vegetative matter and other materials since the first appearance of anatomically modern humans and continuing into current times (e.g., Ambrose 1998;Clark and Kleindienst 2001;De Beaune 1993;Leakey 1971;Maguire 1965;Rosso et al 2016;Van Peer et al 2003;Yellen et al 1995). There are, of course, differences between the grinding-stone tool repertoires used by foragers during the Middle Stone Age and those used more recently in Africa.…”

A Raman micro-spectroscopy study of 77,000 to 71,000 year old ochre processing tools from Sibudu, KwaZulu-Natal, South Africa

“…The small size of the pebble and the presence of use wear and residues mainly on its thin edges imply that it was used for a fairly precise task, maybe for blending composites that included ochre. Pebbles bearing red and yellow ochre residues were also found in Middle Stone Age contexts at the Porc-Epic Cave in Ethiopia [4] and in early Middle Stone Age occupations in Sudan [62]. Rounded pebbles are generally considered to be upper grindstones [4] and the Sibudu Still bay pebble is likely to have been one.…”

“…Pebbles bearing red and yellow ochre residues were also found in Middle Stone Age contexts at the Porc-Epic Cave in Ethiopia [4] and in early Middle Stone Age occupations in Sudan [62]. Rounded pebbles are generally considered to be upper grindstones [4] and the Sibudu Still bay pebble is likely to have been one. The triangular grindstone fragment (Fig.…”

“…The iron oxides and oxyhydroxides present in ochre are, for example, haematite, goethite, and magnetite, and the secondary compounds are minerals associated with rocks such as quartz, clay, and mica. It also leaves a coloured streak when rubbed against a harder material [2][3][4][5]. Some ochre fragments from Middle Stone Age occupations bear use traces of rubbing, grinding, scoring or what appears to be deliberate engraving [6,7].…”

Did Human Reality Denial Breach the Evolutionary Psychological Barrier of Mortality Salience? A Theory that Can Explain Unusual Features of the Origin and Fate of Our Species

“…It is also true that theory of mind is not a clearly definable concept, that some other mammals and birds may have something approaching a full theory of mind, and that Neanderthals have left some evidence for an extended theory of mind, including burials and injured elderly individuals who must have been cared for (Ekshtain & Tryon, 2019;Morin & Laroulandie, 2012;Nakahashi, 2017;Pettitt, 2010;Staubwasser, Drăgușin, Onac, et al, 2018). Considering the archeological record, stone tool production must have required some degree of teaching, verbal communication, or at minimum active demonstration that was occurring prior to the appearance of modern humans (Asfaw, Gilbert, Beyene, et al, 2002), and the production of ochre pigment (Rosso, Pitarch Martí, & d'Errico, 2016), and long-range transport of obsidian toolmaking materials (Blegen, Jicha, & McBrearty, 2018) also predates evidence for modern humans. Meanwhile, some would suggest that the biological sex drive should have superseded fear of mortality salience or that extended theory of mind and reality denial could have coevolved gradually.…”