to medium grade. Its upper reaches show upper greenschist facies conditions, the lower sections reached already lower amphibolite facies conditions. The presence of chlorite and chloritized biotite in shear bands and in pressure shadows indicates retrograde metamorphism, which has been known in the southern Limousin for quite a while. Structural evolution Like the Génis Unit the Thivier-Payzac Unit was also affected by upright ductile shearing. But unlike the Génis Unit it does not possess a uniform shear sense. In the south the unit shows the same dextral shear sense as the Génis Unit right to the anticline at Saint-Mesmin. Farther to the northeast this is superseded by a mixed zone where both shear senses are present. When finally the northern outcrop band of the Thiviers sandstone is reached only sinistral shearing is preserved in the rocks. This sinistral shear sense becomes clearly evident close to the Estivaux Fault. Here the shear coefficient γ takes on the value of 5.4 which represents an accumulated left-lateral displacement of about 30 kilometers. As regards the granitoids the Saut-du-Saumon orthogneiss is affected by two shear senses whereas the Estivaux granite has been deformed solely left-laterally. The following microtectonic methods underline the sinistral shear sense in the northern outcrop area of the Thiviers sandstone: analysis of quartz <c> axes – displaced in the direction of shearing – sinistral. interpretation of asymmetric quartz pressure shadows around garnet – clearly sinistral. interpretation of porphyroclasts of the σ-type (in the Thiviers greywacke). interpretation of shear bands – clearly sinistral (in the Donzenac schist near Allassac). interpretation of quartz pressure shadows on biotite porphyroblasts – sinistral. North of Saint-Cyr-les-Champagnes the neighbouring Upper Gneiss Unit also shows a left-lateral shear sense (sinistrally sheared quartz lenses). In the Donzenac Schist, where both shear senses are present, one can observe how the dextral shearing is overprinting the sinistral shearing. The sinistral movements happened therefore later. On left-laterally sheared, sigmoidal porphyroblasts of biotite dextral shear bands are superimposed on; additionally retrograde chlorite formed in these late shear bands. The pervasive shearing is responsible for the folding in the Thiviers-Payzac Unit; the folds can be interpreted as tear folds that were rotated into the maximum stretching direction in a transpressive, ductile shear zone. The tectonic movements didn't stop at the close of the ductile deformations. For instance in the brittle realm many small, mainly NE-SW-striking strike-slip faults were initiated with left-lateral displacements in the