Metamorphic and Tectonic Evolution of the Hwacheon Granulite Complex, Central Korea: Composite P-T Path Resulting from Two Distinct Crustal-Thickening Events

Abstract

of the HGC. This decompressional process, probably initiated in The Hwacheon granulite complex (HGC), occupying the norththe kyanite stability field, reached pressures of >3–6 kbar at eastern margin of the Gyeonggi massif, consists mainly of gar660–750°C. The clockwise P–T path may reflect the exhumation netiferous leucocratic gneiss and leucogranite together with minor of a deep-seated crustal segment along discrete, ductile shear zones kyanite–garnet gneiss, aluminous gneiss, mafic granulite and garnet during the Permo-Triassic collisional orogeny prevalent in Far-East amphibolite. Mineral assemblages and reaction textures in various Asia. rock types of the HGC document five distinct metamorphic stages: pre(M1) and peak (M2) granulite-facies metamorphism; lower temperature, high (M3) and low (M4) pressure upper amphibolitefacies metamorphism; and local retrogression (M5) producing andalusite-bearing assemblages. Each metamorphic stage can be in