dAf 92
SÉARA Frédéric, ROTILLON Sylvain et Christophe CUPILLARD (éds)
Campements mésolithiques en Bresse jurassienne
Choisey et Ruffey-sur-Seille
A combination of paleo-environmental and archaeological analytical methods has provided information on Ruffey and Choisey-sur-Seille, two open-air sites from the Mesolithic period. It has thus been possible to determine the environmental framework of the camps. Study of finds distribution, stone-tool industry, the origins of flint raw materials and faunal remains has enabled archaeologists to reconstruct the camps’ spatial organisation and to better definethe cultural identity of hunter groups. Excavations at Ruffey produced a significantdiscovery : one of the oldest cremation burials from the middle Sauveterrian. Evidence of different cultural groups passing through the Bresse area of the Jura confirms the Franche-Comté’s role as a crossroads.
Abstract
Abstract
1 Presentation
The two sites studied here are situated in the floodplains of the river Doubs and the Seille, downstream from the last hills of the Jura mountains, in the eastern part of the Bresse Basin. Whilst the drainage basin of the Doubs is very large, that of the Seille is small. During the Lateglacial and Holocene period, Choisey was in a marginal position with respect to the active tract of the Doubs. This is in contrast with the site at Ruffey-sur-Seille. However, both of them fit in with a series of Mesolithic cave or rock shelter sites which have been excavated in the region: Rochedane, Ranchot, Bavans… The study of the different occupation levels recognised at Choisey and Ruffey is based primarily on data concerning the spatial organisation.
2 The chronological and stratigraphical framework
The alluvial formations were recorded using long, cross-sections. It was possible to define several sedimentary groups which composed two sequences at Choisey and four at Ruffey. The chronological calibration of these sequences was possible through radiocarbon dating of the former channel deposits and the occupation layers.
At Choisey, the recorded sedimentary history is short and covers part of the Younger Dryas period and the start of the Holocene, just up until the Boreal period. The Mesolithic remains fit into two groups close to the surface. The upper layer was disturbed by proto- historic structures. At Ruffey, the stratigraphy had been cut by palaeo-channels and is more complicated. The sedimentary record is continuous from the Older Dryas to the SubBoreal periods and the sedimentary context of the early Mesolithic and the Sauveterrian occupations differs from those of the later Mesolithic.
3 The palaeo-environmental study
At Choisey, the first sedimentary sequence from the Older Dryas to the Subatlantic corresponds with a slow alluvial aggradation between the end of the glacial period and the Boreal: these deposits evolve by soil formation processes up until the Subatlantic, without any bearing from the river. The second sequence is a brief episode of sedimentation related to the installation of a 1st century roman villa.
At Ruffey, the first sequence covers the end of the Pleniglacial and the start of the Lateglacial periods. The second starts with renewed alluvial build-up during the Older Dryas. Between the Preboreal and Boreal periods, flooding gets rarer and the multi-thread channel evolves in a single one, stable bed whilst the vegetation cover comes into being. A phase of soil development affects the flood deposits. During the Boreal period, the pleniglacial topography is levelled. Flooding starts off again during the early Atlantic period. This marks the start of the third sequence which finishes with a new phase of soil formation in the later Atlantic period. The last sequence starts in the Subboreal with the recommencing of river activity. After a major cut caused by flood channelling at the end of this period, the site finds itself away from the river’s activity.
The stratigraphy of these two sites is only comparable during the end of the Glacial and the start of the Holocene periods. After the cooling down of the Older Dryas, the Preboreal and Boreal periods correspond to a time of adjustment of the river systems, tied in to the development of the vegetation. The climate cooling of the Boreal is scarcely visible in the sedimentary record and the climatic signature only reappears during the later Atlantic period: it seems to be related to increasing human pressure on the environment.
4 Archaeological studies
The cultural identification of the groups of hunters is based on the typological study of the lithic industry.
The petrographic analyses revealed the use of sources of material often very distant from the place of use. At Ruffey, a clear evolution of the stone supply is visible, marked by a reduction of the exploited area and the massive use of local chert: during the early Mesolithic, the primary materials came from the tertiary basin of the Upper Saône (70 km away). At Choisey, the zone of provision is vast with the utilisation of flints from the tertiary basin of the Upper Saône (50 km away) and of the Kimmeridgian layers from the areas of Dasle or Olten in Switzerland (120 to 185 km away).
All the lithic material (some 24,000 pieces) was taken into account for the technological study, partly based on the refitting of knapping wastes. The blade production shows a continuity in the technique throughout the first two millennia: it is based on the use of hard or soft direct percussion on prismatic nuclei with smooth or flat striking platforms and having had no particular preparation. During the later Mesolithic, the production of regular blades obtained by indirect percussion appears. This results in regularly furrowed nuclei and by heavy faceting of the heels of the blades.
The typological evolution of the Mesolithic material at Ruffey is marked by the reduction of the number of projectile points: during the later Mesolithic, only trapezoidal points are used. The Preboreal industries show much contrast, dominated by transversal bases and isosceles triangles, or by scalene triangles or by isosceles triangles and Sauveterrian points. These last characteristics (without the isosceles triangles) are found during the Boreal period. At Choisey, the Preboreal industries are dominated by points with natural or unworked bases and isosceles triangles. Those from the end of the Preboreal or the start of the Boreal periods consist of segments and points with retouched bases. The catalogue of projectile points is completed by tools common to all periods.
At Ruffey, the oldest periods of occupation belong to two cultural domains. The first occupation (calibrated to 8,400 - 8,000 B.C.) can be attached to the Beuronian domain with a mainly northerly influence. The second (8,400-7,600 B.C.) belongs to the Sauveterrian culture which we find during the middle Mesolithic (7,900-7,100 BC). The later Mesolithic also has references to the southern domains.
At Choisey, the most recent occupation occurred around 8,100 BC and can be attached to the middle Mesolithic of the Doubs valley. The older level, dominated by points with natural or unworked bases, approaches a local variation of the lower Mesolithic, derived from the Arhensbourgian or epi-Arhensbourgian cultures.
The faunal remains represent one of the most important regional series of the Mesolithic. At Choisey, red-deer dominates the older Mesolithic. At Ruffey, wild boar is predominant during the Beuronian period, with boar and aurochs during the lower Sauveterrian, red-deer during the middle Sauveterrian and aurochs during the later Mesolithic. Beaver, roe-deer, fox and wolf are also present. The strong representation of certain species and of certain skeletal remains suggests more or less specialised hunting patterns at Ruffey.
The site of Ruffey also yielded one of the oldest cremation burials, attributed to the middle Sauveterrian period.
The study of the distribution of the remains by category allowed an approach to the understanding of the spatial organisation of the Mesolithic camps. The domestic activities are organised in an area around the key structure, a simple open hearth. This may or may not be in a central position. Of the domestic wastes, the larger “clutter” (bones and flint nuclei) are pushed towards the outside. Shelter or sleeping zones not having been identified on the site, we have introduced the idea of activity units rather than that of habitation units used for the upper Palaeolithic. The restitution of the lithic material coming from different units allows us to specify the notion of a camp: it may correspond to that of a single unit, or to the conjunction of several units, each with the same configuration.
5 Synthesis and hypotheses
Our study shows the great interest, or rather the necessity, of co-operation between archaeologists and palaeo-environmental specialists. An alluvial context seems to be a privileged framework for the conservation of Mesolithic occupations.
The differing cultural origins of the various groups underlines the “cross-roads” role of the Franche-Comté and the complexity of the Mesolithic occupation in this region. The economics of the acquisition of raw materials and animal-based resources indicates the exploitation of large territories and a hierarchy of sites, as shown by the occupations at Ruffey.
