Mechanisms of mass and heat transport during Barrovian metamorphism: A discussion based on field evidence from the Central Alps (Switzerland/northern Italy)

摘要: [1] Tectonic and metamorphic data for the Central Alps (Switzerland/Italy) are used to discuss this classic example of a Barrovian terrain, notably evolution its thermal structure in space time. Available P‐T‐t indicate variable contributions advective conductive heat transport during collision subsequent cooling exhumation. Some areas experienced prolonged period partial melting while other areas, at same time, show but moderate heating. The Barrow‐type field gradient observed final orogen is result two distinct tectonic processes, with their related processes. processes (1) accretion material within subduction channel decompression emplacement high‐pressure units middle crust (2) wedging nappe formation continental lower plate. second process postdates first one. Wedging underthrusting plate produces input into crustal levels, responsible predominantly overlying units. interacting lead different maximum temperatures times, producing gradient. south rapid cooling, whereas north shows rates. This discrepancy principally reflects differences temperature distribution deeper prior cooling. Differences local that prevailed before also determined relationships between rate exhumation areas. Citation: Berger, A., S. M. Schmid, Engi, R. Bousquet, Wiederkehr (2011), Mechanisms mass metamorphism: A discussion based on evidence from (Switzerland/northern Italy), Tectonics, 30, TC1007, doi:10.1029/2009TC002622.