Metapelitas de alta presión de la Unidad de Santiago (Complejo de Ordenes, NO del Macizo Ibérico)

Abstract

A high - pressure - low - to intermediate temperature eo - Hercynian metamorphic event characterizes the tectonothermal evolution of the Santiago Unit, in the western margin of the Ordenes Complex. P-T conditions fo r the mineral assemblages of the high - pressure event (which is essentially preserved as a very thin Si=S1 included in albite porphyroblasts in semipelitic schists) have been estimated at 493 ± 9 °C and 14.7 ± 0.7 kbar (minimum pressure). The development of the high - pressure metamorphism and the lacking of significative reequilibrium of their characteristic mineralogy, suggests that the unit (probably a fragment o f the continental margin of Condwana) has been uplifted inm ediately after undergoing subduction in the beginning of the Hercynian Orogeny