Mantle-lithospheric deformation and crustal metamorphism with some speculations on the thermal and mechanical significance of the Tauern Event, Eastern Alps

Abstract

Changes in the thickness of the mantle lithosphere beneath convergent orogens through processes such as the pervasive thickening of the lithosphere and the convective thinning of the thermal boundary layer dictate the heat flow through the base of the crust and thus may profoundly influence the thermal evolution of crustal metamorphic terrains. Calculations based on one-dimensional thermal-energy balances show that when mantle lithosphere is substantially thickened and remains intact through the orogenic cycle, then low-temperature facies series, including blueschist and eclogite facies, may be preserved throughout the crust. In contrast, crust thickened above attenuated mantle lithosphere w..