The Middle Paleolithic occupation of the Normandy by human groups is well represented by sites, dating to OIS 5d-a and OIS4. There are numerous inventories showing exclusively the production of flakes and/or blades. On the other hand, sites with a bifacial production are also present.
At Grossoeuvre (Eure) and Houppeville (Seine-Maritime) the production sequences are heavily dominated by the Levallois unidirectional technique, sometimes associated with
Some sites show evidence of an “Upper Paleolithic” laminar production sequence(Siouville, Tréauville, Le Rozel, Saint- Germain-des-Vaux / Port-Racine).
The site of Bons-Tassily is an example of a predominantly bifacial lithic production. It was detected during surface surveys during the 1990ies. Thousands of artifacts including hundreds of bifacial tools were found. On geological grounds it can be dated to early Würm, between 80 and 40 k.a. BP. The operational sequence ending in average sized flakes includes an unipolar (or bipolar) Levallois technique. Some blanks had been retouched into scrapers. Many bifacial pieces are of small dimensions and include triangular, subtriangular, cordiform and subcordiform handaxes.
Another famous site in the Normandy with a workshop character is Saint-Brice-sous-Rânes, where beside numerous bifacial tools, a non-Levallois technique prevailes (http://www.aggsbach.de/2011/10/bifacial-tools-from-saint-brice-sous-ranes/)