Epidote Porphyroblasts in Sambagawa Schists of Central Shikoku, Japan

TOKUDA Mitsuru

HARA Ikuo

Journal of science of the Hiroshima University. Series C, Geology and mineralogy

Epidote grains are commonly found as inclusions in plagioclase porphyroblasts of the schists in the biotite zone of the Sambagawa belt of Central Shikoku, Japan. Two types of fabrics of inclusion epidotes are observed: Type I) though the growth of plagioclase porphyroblasts occurred under non-deformational condition (cf. TAKAGI and HARA, 1979; MAEDA and HARA, 1983a and b), the epidote grains show preferred lattice and dimenssional orientation, in individual plagioclase porphyroblasts forming a single set of schistosity and of lineation. And Type II) the epidote grains occur with random lattice and dimensional orientation in individual plagioclase porphyroblasts, developing as porphyroblasts which contain other metamorphic minerals as inclusions. Only in the schists in which inclusion epidote has the fabric of Type II, matrix epidote appears to develop as porphyroblasts. The appearance of the epidote grains as por-phyroblasts under non-deformational condition appears to have begun earlier to some extent than that of plagioclase porphyroblasts.

eng

HIROSHIMA UNIVERSITY

[ISSN] 0075-4374

[NCID] AA00706718