Abstract
The study of fault displacements in a region of well-dated sequential granitic intrusions suggests a close time relationship between two peaks of deformation and intrusive activity. Mantle-derived basic magmas were associated with both episodes, which are dated as mid-Cretaceous and early Palaeocene. It is concluded that in each case a period of tensile tectonics with mafic dyke injection preceded the intense compressive deformation which accompanied the generation and rise of granitoid magmas. These events may be related to alternations of slow and rapid subduction.