More than 100000 Mousterian flint artefacts were found at Alle, Pré Monsieur. They were distributed over 3 areas and 12 layers: the central area (black layer, layers 4b, 4, 2b and 2), the slope area (layers E, D, C, B and A) and the meadow area (layers 3, 20 and 2). The site is situated on the slope of an anticline bordering the floodplain of the Allaine river, a location which has encouraged soil displacement, to which all layers have been subjected. The sedimentology of the site is examined in Chapter 2, using granulometric, geochemical and micromorphological analyses. Through these, an understanding of the conditions of deposition and a site chronology could be obtained. All attempts at acquiring an absolute date (C-14, amino acid racemization and thermoluminescence) have failed.

Flint knapping seems to have occurred on the surface of altered alluvial sediments dating to the Eemian period. Later, river downcutting led to slope destabilisation and the consequent formation of the layers E, 4 and the black layer at the bottom of the slope. These deposits were then covered by the colluviated layer 2b. All of these events seem to have taken place during the Lower Pleniglacial. Layer C was deposited through solifluction, probably during the Upper Pleniglacial. Considerable Holocene deforestation of the surrounding slopes, resulting from human activity, led to increased sedimentation in the floodplain and raised the position of the Allaine river. The layers deposited on the site after these events were all of colluvial origin. Layer B was the first of these, followed by layer 20, which contains traces of a Late La Tène occupation (2035 ± 55 BP). Subsequently, layers A and 2 were deposited. A roman road was cut into the slope during the first century AD. Alluvial sedimentation within the floodplain continued. Several modern erosion phases complete the sedimentary history of the site.

Classification and origin of the lithic raw material forms the subject matter of Chapter 3. More than 99% of the lithic industry were produced on different types of local flint, found within limestone strata of Upper Jurassic (Malm) age. The exotic flint, present in small numbers, was brought from various regions: the Jura mountains, the Upper Doubs Valley and the banks of the Rhine. Other lithic material was collected in the southern foothills of the Vosges mountains or locally, within alluvial formations (Vogesen- and Sundgauschotter in the Delémont and Ajoie regions or in Alsatia).

The typology and technology of a part of the lithic industry was studied (Chapter 4). All layers seemed to contain quite similar material (belonging to a Typical Mousterian industry, rich in scrapers and notches), yet three different facies could be distinguished. In all three, sequenced multiple production debitage (Levallois technique) seems to have been used to produce tools for " export ", while sequenced single production debitage (unifacial, prismatic, etc.) was used to produce tools for immediate use.

Facies A (layers 2, 2b, A and a part of the material from the layer 4) is characterised by the Levallois technique; cores were often used to exhaustion, the flakes becoming gradually smaller and smaller. The small size of this material is also partly due to the use of a fissured raw material which had to be broken before knapping could take place. Typical tools associated with this facies are the " rhenish " scrapers: oblique scrapers, canted scrapers and convergent scrapers with one arched edge (Bogenspitzen). This assemblage dates probably to the Eemian interglacial (about 130000-110000 BP).

Facies B (the black layer and layer 4b and a part of the flints from the layers 4 and E) artefacts were made of a different raw material, unfissured and with finer grain. After burial, most of these pieces acquired an iron and manganese crust. While the Levallois technique is present, cores were not extensively reworked and there was consequently no diminution of flake size. Simple reduction sequences without core preparation predominate. The small number of tools associated with this facies do not allow its typological characterisation. This assemblage probably dates to an interstadial within the Lower Pleniglacial (between 110000-70000 BP).

Facies C (layers B, C, D and most of the material from layer E) is quite similar to facies A; possibly, the two assemblages are linked. Cores are particularly numerous in these layers, more so than elsewhere on the site. Typologically, the scrapers from this assemblage differ somewhat from those associated with facies A, the " rhenan " types being absent. Facies C also dates to the Eemian interglacial.

On the whole, the Typical Mousterian industry found at Pré Monsieur seems to be older than the Charentian Mousterian (oriental type) found elsewhere in the region, for instance at Pleigne, Löwenburg.

Some of the proposed links between layers could be verified through the application of statistical methods (Chapter 5). Correspondence and cluster analyses were also able to show which classes of objects varied most from layer to layer. The assignment of the various layers to the proposed typological groups was confirmed (layer 2b is associated with layer 4, layer B with layer C). Statistical identification of technological groups was less successful (links between the black layer and layer E and between layers 2 and A). Tools of the eastern type were absent from the black layer but are common in layers B and C. Cores varied particularly strongly from layer to layer while notches and denticulates, socalled expedient tools, were evenly distributed.

Artefact distribution is studied in order to determine whether any of the original spatial relationships between artefacts have survived soil displacement (Chapter 6). Several methods are used (statistics, analysis of debris density, horizontal distribution, object density per volume, distribution of exotic flints, of burnt flints and of refitted flints) with at times contradictory outcomes. A refitting study did not provide significant results. The tendency of flakes and cores to be found together and separate from tools seems to indicate that some of the original spatial organisation has survived the later extensive disturbance.

Translation: Robert Fellner