The Middle Palaeolithic settlement of «Le Fond des Blanchards» was discovered in 1996 in a gravel quarry of the Yonne valley (Paris Basin, France). It is contained in an alluvial sequence, the Gron formation, which overlies the 3 ± m incision floor. The settlement has yielded several prehistoric levels attributed to the Lower or Middle Pleniglacial Weichselian substages. The lower levels (DG, DB, D5, D4, D3 and D2) are interstratified in a sandy bank deposit belonging to a braided channel. A loamy sand representing floodplain deposits contains the upper levels (Da, D1). The D levels result from different occupations in the same natural context, along the river bank. Faunal remains found on the settlement (Reindeer and Horse) attest to cool climatic conditions and an open landscape. The lithic artefacts configuration shows that all stages of flake production in the chaîne opératoire are represented on the site, from the acquisition of raw material to the transformation of blanks into tools. The knapping methods are simple and allow the production of a large diversity in flake morphology; «type-tools» are rare. In the C level knapping results in the production of large flakes to be transformed into scrapers. Found in large numbers, they are structured along the same manufacturing concept: it involves intensive reworking. The techno-functional analysis allowed the transformation modalities to be recreated, and showed the production of various types of blanks where reworking took place in ways specific to the different techno-types. The lithic assemblages of Le Fond des Blanchards have been qualified, on techno-typological criteria, as «Moustérien de type Quina», as described in south-western France. However the last technological and techno-functional analyses allow us to reconsider this attribution. The lithic production systems of Le Fond des Blanchards are both classical Quina-like and as original as Levallois. The production objectives seem to be more varied and the manufacturing of tools leads to the realisation of different morpho-types of quite functionally precise scrapers. The lithic production systems of Le Fond des Blanchards, beyond the typological and technological differences, lead to the revising of our definitions, and to looking anew at the variability of the Neanderthalian lithic industries during the last part of the Middle Palaeolithic.