Noritization and hyperitization accompanied with biotite migmatite, at the mid-stream of Horoman river in southern Hidaka metamorphic terrain (II)

Abstract

At the contact between hornblende tonalite and its xenolith, biotite nortite was formed, while at that of biotite migmatite and amphibolite, biotite hyperite was produced. From the careful observation in the field and microscope the writer attained the conclusion that the norite or hyperite is not originated from gabbroic magma and the inclusion is not ascribed to the forerunner of magma, nor to the amphibolite. Feature of mechanical movement in norite or hyperite is considered to have taken place at the time of formation of biotite migmatite or amphibolite. Metamorphic aspect in biotite migmatite is a kind of “metablastesis”. Dispersion of biotite into matrix, and recrystallization of biotite into pyroxene or hornblende are the general behaviors in this district.