An open-air site from the recent Middle Palaeolithic in the Paris Basin (France): Les Bossats at Ormesson (Seine-et-Marne).

In northern France, most of the sites attributed to the Middle Palaeolithic are open-air sites in
which mainly lithic artefacts are found, due to taphonomic conditions often unfavourable to
the preservation of fauna. The lithic assemblages found in most of those open-air sites suggest
that the activities on the camp sites were diversified, although flint knapping was often
intense due to the proximity of sources of raw siliceous materials. With the exception of very
rare open-air sites, fauna is poorly preserved and spatial and economic analyses may often be
based on the spatial distribution of lithic artefacts, in particular based on refits and their
analysis. Therefore the palaeoethnological approach is difficult to implement in most open-air
areas. In contrast, in the Paris Basin, the study of more recent sites from the Tardiglacial, such
as the Magdalenian sites of Pincevent or Etiolles, falls within this approach. The recent
discovery (2009) and excavation of the open-air site of Ormesson (Seine-et-Marne - France)
was initially intended to document a Gravettian occupation floor dated around 26,000 years
uncal BP and related to a preferential bison hunt. Whilst checking the thickness of the loess in
which the Gravettian level was found, several other prehistoric settlements were discovered
(Chatelperronian, Middle Solutrean) including two units attributed to the Middle Palaeolithic.
One of them, level 4, seems to be particularly well-preserved. It occurs between one and three
meters below the main Upper Palaeolithic occupation. The lithic industry from level 4
belongs to a technical tradition generally attributed to the Middle Palaeolithic: discoid
technology. The freshness of the material and the presence of bone fragments attributed in
part to horse support a general good state of preservation of this occupation. The Mousterian
remains seem to cover at least 500 m2, as currently estimated. Even more exceptional is the
close spatial relationship between the discoid industry, the bone pieces, remains of fireplaces
and especially the numerous fragments and nodules of red colouring materials. These were
brought to the site where they were utilised by the Mousterians. The used surfaces show
indisputable scraping traces and facets. These recent discoveries will certainly contribute to
the debate on the cognitive capacities of nearly the last representatives of the Middle
Palaeolithic and this within a complex stratigraphy which will allow us to make comparisons
between the different periods.