Official Tourism Website of Mount Fuji in Yamanashi Prefecture "Home of Mt.Fuji, Yamanashi" > Mt. Fuji > The History of FUJI VOLCANO
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Presently, Mt Fuji consists of Three Parts:

Komitake Volcano which now forms the northern part of Mt. Fuji first erupted 700 thousand years ago, emitting sticky lava and lapilli for a long time. At the same time on the southern part, Mt. Ashitaka was also erupting. Mt. Komitake was about 2,500 meters high.

An Older Fuji Volcano was newly erupted on the south side of Komitake Volcano. The violent activity sent out brass-colored volcanic mud flows in all directions. It is considered that it became a large strato-volcano with a height of about 2700 meters.

About 10 thousand years ago, the eruption of a Younger Fuji Volcano broke out from the nearest region to the central crater of the Older Fuji Volcano.
The Younger Fuji Volcano continously emitted a less stickier lava, volcanic ash, sand and lapilli than its predecessor. Anout several thousand years ago, it buried Komitake Volcano and the Older Fuji Volcano, adding to its height and finishing the orogenic movement.
At present Mt. Fuji is 3776 meters high.