Cross sections of the French Massif Central. The location of the cross sections (A-A’, B-B’, C-C’, and D-D’) is indicated on the geological map Figure 2. Same legend as Figure 3 with the addition of a granulitic lower crust intruded by mantle-derived mafic magmas. The upper part of the sections is constrained by field observations. The shaded lower part of the sections is less constrained and is based on scarce geophysical data that allow the prolongation of some structures at depth and on exposed sections of the Variscan lower crust in the Southern Alps (Ivrea Zone) and in Calabria.