Les matières colorantes sur le site aurignacien de plein air de Régismont-le-Haut (Poilhes, Hérault) : acquisition, transformations et utilisations
Authors: Pradeau Jean-victor , Salomon Hélène , Bon François , Mensan Romain , Lejay Mathieu , Regert Martine 
Published: May 2017

The onset of the Early Upper Palaeolithic is represented by few open air camp-sites in southern France. Most of the archaeological record is documented by sequences of occupations in rock shelters or at the base of rocky cliffs. These contexts offer favorable conditions for the preservation of organic materials, but the areas excavated are small, limiting our understanding of the spatial relationships between the remains of the human occupations. Knapped stone associated with consumed fauna are often accompanied by colouring materials, stones rich in iron and manganese oxides (hydroxides). This class of materials has rarely been analysed, and the objectives for their extraction and transformation still remain an open question. While this class of mineral materials collected in karstic contexts is relatively abundant, understanding of the motivations for their exploitation is made difficult by the lack of spatial data, which seems crucial to explain this industry within the technological systems of the Early Upper Palaeolithic. Régismont-le-Haut (Poilhes, Hérault, France) is one of the rare open-air sites dating from the onset of the Early Upper Palaeolithic known in southern France with taphonomic conditions that enabled the preservation of occupation structures and well-delimited activity areas. This Aurignacian camp was established in two perpendicular inactive palaeochannel depressions, progressively filled by the erosion of a neighbouring hill, nowadays entirely levelled, via a colluvial process mixed with aeolian contributions. This configuration led to the exceptional preservation of the occupation level within these two palaeo-channels ; it consists of a single nearly undisturbed living floor, forming two main areas with a clear spatial separation. Around twenty combustion structures have been discovered. These act as poles of activity around which the artefact concentration is found more or less dispersed across a very thin layer : flint and quartzite, large limestone tools, charcoal, poorly preserved bone, malacofauna and colouring materials. The colouring materials are found in different forms : raw or partially transformed blocks of raw material (mainly red, but also yellow and black), friable chunks probably resulting from some preparation (red), red powder residues on lithic elements, in particular scrapers in siliceous materials, and on body ornaments of shell beads, red impregnations in the sediments. Attention has been focused on the blocks of raw material in order 1) to identify the geomaterials brought to the site and their specific properties (colouring potential, hardness, etc.), 2) to describe the processing sequences for the preparation and transformation of these materials and 3) to initiate a discussion on the patterns of means of utilization and the intended functions of colouring materials at Régismont-le-Haut. The entire dataset has been analysed by binocular microscope and classified by petrological range. A sample of these different classes was described by observations at high magnification, element analysis (scanning electron microscopy and energy dispersive X-ray spectroscopy : SEM-EDX) and structural analysis (X-ray diffraction : XRD). These results were then interpreted with respect to the spatial distribution of the artefacts. Seven classes were discriminated, based on several petrographic criteria (matrix texture, kinds of inclusions, mineral structure). Some can be paired and may come from the same geological facies. The main geomaterial brought to the site is heterogeneous, in majority composed of haematite, sometimes goethite, associated with quartz, calcite and muscovite ; these can have a significant degree of hardness, which requires tools to transform them to powder. The second broad range of red material is composed of soft blocks rich in haematite, kaolinite and calcite, with small grains of muscovite. Much less common, goethite, lead compounds (cerusite and galena), kaolinite and dolomite form the yellow lumps. The rare black blocks are all manganese oxides. The elemental, mineralogical and petrographic characteristics of the raw materials point to a broad-spectrum acquisition typical of the regional geological environment around the site, as shown by our preliminary raw-material sourcing surveys. The sequences of transformation are primarily characterized by the mechanical operations requiring crushing/ grinding while the softer blocks rich in haematite and kaolinite could be exploited by simple rubbing on a soft support. Preparation of powder by scraping and abrasion is not as yet documented. In addition, heat treatment was not performed systematically. The intended functions of the colouring materials and their means of utilization, although difficult to assess, seem to cover a wide range of activities, here clearly separated at the site according to the raw materials used. In particular, the association between hide-working activities and materials with high colouring capacity could be demonstrated at one of the loci on the site of Régismont-le-Haut (S56). The utilization of colouring materials is also documented in another locus (S72), probably linked rather to the primary processing of carcasses. In both cases, the prehistoric group exploited haematite for its intense colouring capacity for purposes that it is not possible to reconstruct precisely, given the complete destruction of any organic supports to which colouring could have been intentionally applied (hide, clothing, tools, etc.), but the use of colouring materials for technical purposes — for example their drying power to preserve organic materials or keep the ground clean, and their abrasive power to process bone or hide — is quite probable.