Misaka Metamorphic Rocks in the Southeastern Margin of the Tanzawa Quartz-diorite Massif

In the present paper are described the petrographical characters of various metamorphic rocks distributed along the southeastern margin of Tanzawa quartz-diorite massif. The metamorphic rocks in this area are derived from the Misaka Series consisting of basaltic to andesitic pyrocrastics and associating diabase lava-flow and dikes, and are divided, from their mineral compositions, into Amphibolite- and Actinolite-green schist-Facies. The former, consisting mainly of intermediate plagioclase and green common hornblende, is restricted to the very contact of the quartz-diorite massif. The latter occupies the outer area, and consists mainly of actinolite. It is noteworthy that these metamorphic rocks are utterly lacking schistosity. These metamorphic rocks seem to be products of contact metamorphism due to the intrusion of quartz-diorite. In Table I are shown the minerals of the main original rocks and their metamorphic derivatives