Mount Ontake
When the Wadati–Benioff zone (earthquake foci in the mantle) is less than 200 km deep, tholeiitic basalt magmas are produced (Izu Ōshima, Mount Hakone for instance). At intermediate depths high-alumina basalt magmas are formed (Mount Fuji, Southern Yatsugatake Volcanic Group, Mount Ontake, for instance) and at depths greater than 250 km alkali olivine basalt ones (Oki-Dōgo, for instance). Hisashi Kuno contributed to unfold this causal correlation.