Orogeny and ophiolites: plate tectonics revisited with reference to the Alps

Abstract

We develop a geodynamic scenario that explains many features of Alpine orogeny and ophiolite thrust sheet emplacement. Important elements of this scheme are: 1. age-dependent subduction and a related compressive regime upon the closing of small and young oceanic basins. 2. the induction of thermal upper mantle anomalies by spreading and lithospheric doubling and subsequent apparent migration by lithospheric shifting. It is shown that these processes. which have hitherto not been taken into account in intra-continental tectonics, play a crucial role in mountain building. This applies in particular to their function in gravity tectonics, metamorphosis and post-orogenic epeirogenesis and foreland uplift.