%0 Journal Article
%A Escuder Viruete, J.
%A Indares, A.
%A Arenas Martín, Ricardo
%T P-T path determinations in the Tormes Gneissic Dome, NW IberianMassif, Spain
%D 1997
%@ 0263-4929
%U https://hdl.handle.net/20.500.14352/57762
%X The Tormes Gneissic Dome (TGD, NW sector of the Iberian Massif, Spain) is a high-grade metamorphiccomplex affected by a major episode of extensional deformation (D2). The syn-D2 P-T path of the LowerUnit of the TGD was deduced from the analysis of reaction textures related to superimposed fabricsdeveloped during exhumation, analysis of mineral zoning and thermobarometric calculations. It comprisesan initial phase of decompression, determined using the TWEEQU thermobarometric technique, from6.4-8.1 kbar at 735-750 DC (upper structural levels) and 7.2 kbar at 770 DC ( lower structural levels) to3.3-3.9 kbar and 645-680 DC. This evolution is consistent with the observed sequence of meIting reactionsand the generation of garnet- and cordierite-bearing anatectic granitoids. The later part of the syn-D2P-T path consisted of almost isobaric cooling associated with the thermal re-equilibration of the unit inthe new structural position. This segment of the P-T path is recorded by assemblages with And + Bt + Msand Ms + ChI + Ab related to the later mylonitic S2 fabrics, which indicate retrogression tolow-amphibolite and greenschist facies conditions.
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