How did Mt. Fuji come about?
Shin(new)-Fuji volcano(about 10.000 years ago)

About 10,000 years ago, volcanic activities changed to flow a large amount of lava; and then the eruptions started at almost the same location as the central crater of Ko-Fuji volcano, marking the beginning of the activity of Shin-Fuji volcano.
This Shin-Fuji volcano grew to a height of 3,776m above sea level by covering both volcanoes Komitake and Ko-Fuji with basaltic lava.
This is the current Mt. Fuji, born about 100,000 years ago, and taking the current shape since about 10,000 years ago.