R6: Plutonic rocks, volcanic rocks and subduction factory

[R6P-07] Geochemical features of the Early Miocene Hachiya Formation
in the Chuno Area, Gifu Prefecture, Japan

[Presentation award entry]

*Seiya Saijou¹, Toshiro Takahashi² (1. Niigata Univ. Sci., 2. Niigata Univ)

Keywords:Hachiya Formation, adakite, slab melting

The Hachiya Formation in Chuno area, Gifu Prefecture, is composed of pyroclastic rocks of the Early Miocene, is seen on the front arc side of the volcanic front at that time. However, detailed Geochemical studies of this have not been done. We studied this to understand the igneous activity in southwest Japan at that time. This shows that this formation may have originated in slab melts that reacted with the mantle, continental lithospheres.