The writer presents some considerations on the genesis of some basic schistose rocks in the southern Hidaka metamorphic province.
The basic schistose rocks described here are the schistose-plagioclase amphibolite (fine grained rock), the plagioclase amphibolite (medium grained rock) and the hornblende-plagioclase gneiss (coarse grained rock).
It is concluded that most of the fine or medium grained basic schistose rocks are originated from the biotite rich hornfelsic rocks and the coarse grained basic schistose rocks are from the coarse biotite rich quartz-biotite-plagioclase rocks. The former two are products at the earlier stage of metamorphism and the latter is a product at the later stage of metamorphism in this district.