Resumen de High temperature - Low pressure tectonites from the Boa Fé Fault Zone (Évora Massif, Ossa Morena Zone, Portugal): Evidences for transtensional tectonics
M. Chichorro, M. Francisco Pereira, Arturo Apraiz Atutxa, J.B. Silva
Partial melting in the Évora Massif (Ossa-Morena Zone) occurred contemporaneously with non-coaxial deformation in a transcurrent regime.
An example of this fact has been taken from studied partially melted biotite-sillimanite-K-feldspar-andalusite-cordierite tectonites from the Boa Fé Fault Zone. These HT-LP (- 2,5-3.5 kbar and 550°-750°C) mylonitic rocks characterized by a steeply dipping to SW foliation (N30º-55°W, 70º-80ºSW) and gently dipping to SE stretching lineation (10°-20° to SE) associated to sinistral sense of movement. Transtensional tectonics ís suggested to explain how the Évora High-grade Metamorphic Terrain migmatites were exhumed in parallelism with the orogen-trend.
