12000 years of human occupation, 3 meters deep stratigraphy, 12 hectares… A geographical information system (GIS) for the preventive archaeology operation at Alizay (Normandie, France)

Abstract : An archaeological investigation carried out by INRAP (Institut national de recherches archéologiques préventives) revealed that banks of the river Seine at Alizay (Normandy, France) were occupied during 12000 years. The specifications of the excavation were to study various occupations (Upper Palaeolithic, Neolithic, Iron Age and Middle Age) applying the appropriate methodology for each major period. A Leica TS15 robotic total station was used to rapidly record archaeological features and store directly in the field pre-formatted GIS data. The aim of the process was to inventory and study, during the excavation, the 120 000 exhumed artefacts using a Microsoft Access database linked to a geodatabase in Esri ArcGIS. This specific archaeological information system was designed to guide the earth removal, by producing digital elevation model of each stratigraphic context, facilitate the management and inventory of artifacts and spatialize the data produced during the excavation.