高原山

Takaharayama is a small stratovolcano with lava domes located SW of Nasudake volcano and NNW of Utsunomiya city in central Honshu. The basaltic-to-dacitic volcano lies within the Shiobara caldera, which was formed during the late Pleistocene at the time of the eruption of the Otawara pumice-flow deposit. The latest dated eruption of Takahara took place about 6500 years ago along the NW-SE-trending Yumoto-Shiobara fissure system within the caldera. Eruptions along this fissure initially produced the phreatic Takahara-Uenohara tephra deposit, which was distributed primarily to the east. The symmetrical Fujiyama lava dome, one of many conical volcanoes named after Japan's renowned Mount Fuji, was extruded at the end of the eruption.