Image

Complex arrays of laterally extensive movement zones occur beneath the Austro-Alpine 'cold lid' of the European Alps. These shear zones operated as extensional movement zones at various times during the tectonic evolution of the Alps, however meso-scale and micro-scale structural analysis show the tectonic history to be more complex with period of shortening and extension to have operated in a zone that we call 'Shuffle Zones'. Shuffle zones are characterized by slivers and/or lenses of exotic rock juxtaposed against rock metamorphosed and deformed at different pressure and temperatures during the tectonic history. 40 Ar/ 39 Ar geochronology is used to determine the timing of deformation across the crustal-scale shear zones and is used as a tool to define the deformation history of complexly deformed zones.