DEFORMATION AND KINEMATICS OF EMPLACEMENT OF THE AXIAL DOME OF THE MONTAGNE NOIRE - IMPLICATIONS OF QUARTZ-SILLIMANITE NODULE ATTITUDES (FRENCH MASSIF-CENTRAL)

Sillimanite nodules of the Espinouse massif are important features for describing the strain that prevailed at the climax of metamorphism. A t this stage, the Axial Zone was already an antiformal structure affec ted by extensional unroofing. Occurrence of the sillimanite nodules mo stly in the aureole zone of a granite recently dated at 327 +/- 5 Ma, implies that extensional deformation defined by sillimanite modules an d low-angle shear zones was active at the end of the Visean and conseq uently, contemporaneous with the latest stage of nappe overthrusting a nd stacking in the southern limb of the Montagne Noire.