Late Variscan events in the outer Ligurian Briançonnais.

Abstract

In ihe Ligurian Brian9onnais domain a late Variscan sequence of volcanie, mainly ignimbritic, and sedimentary continental deposits filled up graben and halfgraben struciures,bordered by two seis of syngeneticfaults (presently trendingnearlyE-Wand N-S), during tree man phases. The oldestone,ofWestphalian-Siephanian age, was accompanied by calc-alkaline rhyolite; ihe second one, of middle (7) Siephanian age, is marked by «shoshonitic» andesites; te last, early Permian one, gaye buge volumesof calc-alkaline rhyolitic to dacitic volcanics and was closed by a K-rhyolitic event. No volcanism is associaied with te uncamformably overlying late Permian continental coarse deposiis (Verrucano).