VARISCAN CRUSTAL EVOLUTION IN THE VOSGES MOUNTAINS AND IN THE SCHWARZWALD - GUIDE TO THE EXCURSION OF THE SWISS-GEOLOGICAL-SOCIETY AND THE SWISS-SOCIETY-OF-MINERALOGY-AND-PETROLOGY (3-5 OCTOBER, 1992)

The geology of the Vosges Mountains and the Schwarzwald (Black Forest) was studied during a three-day field excursion, which was held after the 1992 meeting of the Swiss Geological Society and the Swiss Society of Mineralogy and Petrology. Recent results of field work as well as petrologic and radiometric investigations concerning the Variscan crus tal evolution of a central segment of the European Variscan belt on bo th sides of the Rhine Graben were presented and discussed. The Varisca n tectono-metamorphism is characterized by a polyphase evolution, whic h develops from crustal collisional shortening until the latest Early Carboniferous to crustal extension at the Lower/Upper Carboniferous bo undary. Stephano-Permian intramountain basins indicate the end of Late Paleozoic uplift.