Fig. 7

Field relations of dyke emplacement: a shoshonitic andesitic dyke crosscutting the high pressure gneiss of the Sesia–Lanzo Zone, showing strong surface alteration and being probably truncated by the formation of the Early Rupelian (see also Zanoni et al. 2008, their Fig. 2a and Plate 1); b calc-alkaline basaltic dyke intruding the Ivrea derived mylonite; the dyke only suffered late brittle deformation; c map of the area of the upper Val Sessera showing the location of the dykes (a) and (b)