Fig. 2: Stratigraphy and chronology of Sion–Anciens Arsenaux.

a Chronological summary of the Ensembles N1, AG1 and N2 (results of the Bayesian modelling). The red density plot shows the Ensemble AG1 comprising the ard marks. The full model is based on 30 radiocarbon dates (see Tables 2 and 3). b Photogrammetry of the lower part of the stratigraphy of the Anciens Arsenaux site, with Ensembles N1, AG1 and N2. c Selection of ceramics from Ensemble N1. Nos. 2–3 are fragments of a hollow-bottomed vase characteristic of the early phase of the Vasi a Bocca Quadrata culture in the Po plain, dated to the beginning of the fifth millennium BCE. d Selection of ceramics from Ensemble N2. No. 5 shows decorations typical of the Planig Friedberg group (about 4600 BCE), mainly found in the Rhine basin. Photogrammetry: ARIA SA; photographs and drawings of the sherds: S. van Willigen, InSitu SA.