The plagioclase garnet hypersthene hornblende rock as a block on the River Horobetsu (the River Niobetsu), in the central migmatite bodies, Hidaka province
The writer describes the petrographical chracters of the plagioclase garnet hypersthene hornblende rock found as a block on the River Horobetsu, Hidaka prov. and gives some considerations on its genesis.