The Mesolithic occupations at Pen Hoot Salaün in Brittany: First results of the excavation and a review of the methods used

摘要

Pen Hoat Salatin, where an area of 3 700 m ~2 was excavated prior to the building of a hypermarket, yielded two occupations, the first related to the Bertheaume group (Early Mesolithic, 8300-8200 BC), the second dating to the end of the Early Neolithic (4800-4700 BC). The site, set at the top of a slope on the edge of a plateau and overlooking a graben, dominates a broad landscape open towards the northeast. This topographic situation favoured the movement of sediments on the hillside and the reorganisation of archaeological levels, which divide into three superimposed units (levels 1 to 3). Stratigraphic distinctions are possible. The bottom level (3) appears as the least perturbed. In a horizontal dimension, it is also possible to distinguish a main concentration (zones E6-F6) encircled by weathered granite beds and another on the slope (zone D4), both attributable to the Early Mesolithic. The Neolithic lithics and ceramics were mainly discovered in the middle level (2) and are linked to a very degraded and unexplored dwelling further south. The radiocarbon dates allow us to place the Mesolithic occupations at the end of the 9th millennium BC, i.e. a little earlier than previously known dates. This dating program also provided an opportunity to alert us to the risk of exclusively using burnt hazelnuts in this kind of sedimentary context. The raw material for reduction processes comes from marine pebbles (98.8% of the lithic pieces). Eocene sandstone and Tremeven ultramylonite are very rare. Bladelets were produced with a semi-rotating exploitation of the core, with a clear differentiation between the centre of the table dedicated to narrow bladelets with a pointed extremity and the edges of this knapping surface, providing wider products (small flakes and large blade-lets) with slightly convex edges, sometimes with a little cortex on the side and a twisted profile. The terminal phase of knapping is bipolar, but it is sometimes bipolar and sequential beforehand. The microliths identified are classical in the Bertheaume group: narrow backed bladelets (2-3 mm) with one or both sides retouched, fairly short scalene triangles, different kinds of points, and some rare isosceles triangles and segments. A large number of pebbles used as percussion tools were found, as well as ochre nodules and an arrow shaft smoother made of sandstone. The lack of structures related to these Mesolithic activities, an observation already made during excavations on other sites, is not due to erosion, but reflects either original cultural practices, or a specific type of settlement in the mobility cycle. Typological similarities will one day allow us to distinguish settlements where plant remains abound and others where they are more sporadic. This variability may depend on local environment differences or seasonal activities. Examining anvils, hammer stones and other massive tools in view of appropriate experiments could be important for research. The typological analogies mobilized in this article allow discussion of cultural links proposed formerly, by developing a new model of interactions between regional technical traditions for the Early Mesolithic. An almost systematic mixture in the levels prevents phasing of these "big stylistic packages". The whole process of typological analogies intended to determine the position of a site in a cultural frame tends henceforth to be reassessed in the light of a different way of considering the stylistic and technical entities of the Mesolithic.