Transición dúctil-frágil en la corteza de la zona central de la Península Ibérica

Abstract

Brittle-ductile transition is estimated on the basis of pore-pressure dependent frictional failure in the brittle regime, and power-law steady-state creep in the ductile regime. Structure and lithological composition of the Central Iberian Peninsula Crust combined with geotherm are used to generate rheological profiles. Two brittle-ductile transitions are shown in the crust. The shallower one is located at ~ 7 km under compressional stresses, and at » 9 km under tensional stresses. The deepest is located at the top of the middle crust, at -14 km in compression and =>17 km in tension regime. Below it, the material is ductile throughout, with a jump in strength at the Moho, which is a main rheological discontinuity. Upper part of lithospheric mantle behaviour is dominated by brittle mechanisms when the crust thickness is 30 km, but ductile mechanisms prevail in 34 km crust thickness