Rosso Daniela Eugenia, Pitarch Martí Africa, d'Errico Francesco
UMR-CNRS 5199 de la Préhistoire à l'Actuel: Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux, Pessac, France.
Seminari d'Estudis i Recerques Prehistòriques (SERP), Departament de Prehistòria, Història Antiga i Arqueologia, Universitat de Barcelona, Barcelona, Spain.
PLoS One. 2016 Nov 2;11(11):e0164793. doi: 10.1371/journal.pone.0164793. eCollection 2016.
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.
赭石是中石器时代（MSA）遗址的常见特征，常被解释为现代行为起源的一种代表。然而，在旨在推断这些人工制品获取、制作和使用所涉及技术步骤的理论框架内，对来自MSA背景的赭石加工工具、赭石容器和赭石染色人工制品进行详细研究的却很少。在此，我们分析了21件赭石加工工具，即上磨石和下磨石，以及两件来自埃塞俄比亚迪雷达瓦波尔克 - 埃皮克洞穴MSA层的赭石染色人工制品，其年代约为公元前40 cal kyr。这些工具以及在该遗址发现的4213块赭石碎片中的很大一部分，都集中在一个专门用于赭石加工的区域。下磨石由多种原材料制成，其中一些并非当地可得。使用痕迹表明采用了不同技术来加工赭石。对人工制品磨损区域保存的残留物进行光学显微镜、X射线衍射、微拉曼光谱和扫描电子显微镜 - 能谱分析表明，为了生产不同粗细和色调的赭石粉末，对不同类型的含铁岩石进行了加工。一块没有用于加工赭石痕迹的圆形石头有一半被残留物覆盖，就好像它被浸入了一种液体赭石介质中以涂抹物体，或者用作印章将颜料施加到柔软材料上。我们认为，在波尔克 - 埃皮克洞穴确定的赭石还原序列反映了高度的行为复杂性，代表了赭石的使用，其用途可能多种多样。
