Variscan orogeny In the Czech Republic and Eastern Poland the Bohemian Massif is the eastern end of the unmodified Variscan belt of crustal deformation in Europe. Further Variscan developments to the southeast are partly hidden and overprinted by the Alpine orogeny. In the Alps a Variscan core is built by Mercantour, Pelvoux, Belledonne, Montblanc and Aar Massif. Dinaric, Greek and Turkish mountain chains are the southeastern termination of the Variscan proper. The Variscan was contemporaneous with the Acadian and Alleghenian orogeny in the United States and Canada, responsible for forming the Ouachita and Appalachian Mountains. North American areas with Variscan foldbelts include
Andean orogeny of the supercontinent Rodinia in the Neoproterozoic. The Paleozoic Pampean, Famatinian and Gondwanan orogenies are the immediate precursors to the later Andean orogeny. The first phases of Andean orogeny in the Jurassic and Early Cretaceous were characterized by extensional tectonics, rifting, the development of back-arc basins and the emplacement of large batholiths. This development is presumed to have been linked to the subduction of cold oceanic lithosphere. During the mid to Late Cretaceous (ca. 90 million years ago) the Andean orogeny changed significantly in character. Warmer and younger oceanic lithosphere is believed to have started to be subducted beneath South