Possible partial melting and production of felsic melt in a Jurassic oceanic plateau of the Izanagi Plate: Insights from 159 Ma plagiogranites from northern Japan

A small tonalite – dacite body has been discovered in the Nakanogawa Group, Hidaka Belt, northern Japan, which is a Palaeogene subduction complex formed palaeo-Japan trench along northeastern margin of Eurasia. The tonalites are characterized by extremely low K2O (0.2–0.3 wt.%) and relatively flat chondrite-normalized rare earth element patterns (La/Yb[N] ~2.3), similar to plagiogranites ophiolites. major-and trace-element characteristics consistent with low-pressure partial melting oceanic crust outside garnet stability field. Zircon U Pb dating yielded weighted-mean 206Pb/238U age 159.1 ± 1.6 Ma. Late Jurassic plateau-type basaltic rocks amount plagiogranitic distributed sporadically complexes arc system. zircon (151.6 1.8 Ma) reported for greenstone Cretaceous palaeo-Kuril block was probably derived from at junction -Kuril systems. Thus, greenstones were likely part large plateau, Izanagi Pacific–Farallon ridge triple during Early Cretaceous.