Relamination and lower crustal flow in collisional orogens
The characteristic feature of the new model proposed for the Variscan orogen in the Bohemian Massif (Lexa et al., 2011; Schulmann et al., 2014; Kusbach et al., 2015) is the convergence of two contrasting domains of lithosphere, leading to subduction of an attenuated felsic metaigneous crust under the rifted (Gondwana) margin formed by a dense sequence of metasedimentary and metabasic rocks. The light lower plate crust forms the lower crustal allochthon attached to upper plate and was called „relaminant“. It was shown that the relamination of refractory light material rich in radioactive elements underneath the relatively dense upper plate is a key process governing further evolution of hot orogenic systems.