Tectono-metamorphic evolution, migmatization and syn-tectonic magmatism from Porto region (NW Portugal) [Evolução tectono-metamórfica, migmatização e magmatismo sin-tectónico na região do Porto (NW Portugal)]
Ribeiro M.A.,Centro Geologia DGAOT |
Martins H.C.B.,Centro Geologia DGAOT |
Sant'Ovaia H.,Centro Geologia DGAOT |
Doria A.,Centro Geologia DGAOT |
And 2 more authors.
The NW of the Porto-Viseu metamorphic belt is characterized by syn-tectonic and post-tectonic magmatism, associated with migmatites. The surrounding metasedimentary rocks show narrow and progressive metamorphic zoning ranging from chlorite to sillimanite zone. The metamorphic paragenesis with staurolite and without cordierite exclude barometric conditions <2 Kb, implying depths ≥ 6-7 km. The upward flow of ductile metamorphic rocks, promoted by the syn-tectonic rising of magmas and melts is indicated by syn-kinematic (syn-D3) staurolite, strong mineral lineation down-dip in S3 plan and the association of migmatites with syn-tectonic granitic rocks. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP. Source