R6: Plutonic rocks, volcanic rocks and subduction factory

[R6P-03] Zircon U-Pb ages of the plutonic rocks in the eastern part of the Abukuma Mountains

*Masumi Mikoshiba¹, Yutaka Takahashi¹, Kazuya Kubo¹, Tohru Danhara², Hideki Iwano², Takafumi Hirata³ (1. AIST, 2. Kyoto Fission-Track Co. Ltd., 3. Univ. Tokyo Sci.)

Keywords:Plutonic rocks, Abukuma Belt, Kitakami Belt, U-Pb age, zircon

U-Pb age dating of zircon for the plutonic rocks in the eastern part of the Abukuma Mountains was carried out. Zircon U-Pb ages of granitic rocks in the Abukuma Belt are 112 Ma and 104 Ma (medium-grained hornblende-biotite granodiorite), 109 Ma (medium-grained pink biotite granite), and 112 Ma (medium to fine-grained biotite granite). As for the granitic rocks in the Kitakami Belt, zircon U-Pb ages are 118 Ma (Kunimiyama Granodiorite) and 112 Ma (Hochijoishiyama Granite).