Fig. 13

Tectonic setting of the early Paleozoic subduction–accretion complex (SAC) exposed in the pre-Mesozoic basement units of the Alps (Zurbriggen 2017). The flow paths of materials are symbolized with different arrows (see left part of legend in the lower box). The dynamics in the subduction channel (Cloos and Shreve 1988; see middle part of legend in the lower box) produce tectonic mélanges, which can be dragged to large depths and rise as cold diapirs. Possible protoliths for amphibolites and associated meta-ultramafics are indicated with numbers (see right part of legend in the lower box). P–T data of eclogites are taken form Franz and Romer (2007), who dated the eclogites of the Strona-Ceneri Zone to be Ordovician