By the studies on the geologic structure, fabric, igneous and metamorphic minerals, and plagioclase twinning of Hadong-Sancheong anorthositic rocks, the metamorphic facies, intrusive age and metamorphic influences for the origin of the rocks are figur...
By the studies on the geologic structure, fabric, igneous and metamorphic minerals, and plagioclase twinning of Hadong-Sancheong anorthositic rocks, the metamorphic facies, intrusive age and metamorphic influences for the origin of the rocks are figured out. The anorthositic rocks are mono-metamorphosed and retrograded from epidote-amphibolite facies to greenschist facies. A transitional phase takes place between the above two facies. The metamorphism in anorthositic rocks is in accord with the third period of the retrograssive metamorphism having a multiple influence on the Sobaegsan Gneiss Complex intruded by the anorthositic rocks. The anorthositic rocks were metamorphosed from late Proterozic and that finished by the time of Jurassic, Daebo Orogeny, which is the same period as that of the so-called Julri Group. The anorthositic rocks are assumed to be intruded in the late Pre-Cambrian age and have no relation with the metamorphism in their origin.