RESPECTIVE EFFECTS OF THE HERCYNIAN TARDI-OROGENIC COMPRESSION AND THEN EXTENSION IN THE STRUCTURAL EVOLUTION OF THE ROSIS SYNCLINE AND CAROUX ANTICLINE (EAST OF THE MONTAGNE-NOIRE AXIAL ZONE, FRANCE)

The orthogneisses and micaschists of the eastern part of the Montagne Noire axial zone resulted from a major early ductile deformation (D-P) which yielded a strong, flat, regional foliation (S-P). S-P was then deformed by three late compressional phases (D-Tl-3) which resulted in cleavages and overturned to upright folds, some of them kilometric in size (Rosis syncline, Caroux anticline). After that, the whole struct ure was affected by an extensional phase (D-TH) which yielded either n ormal microfaults due to shearing or open, recumbent folds. Contrary t o recent claims, this late extension postdated the dome pattern in the studied area and only scarcely altered it. Events here displayed matc h very well those previously recognized in the south of the Velay dome .