R8: Metamorphic rocks and tectonics

[R8-08] The time-scale conundrum of jadeitites: How long retained in forearc mantle wedge?

*Tatsuki Tsujimori¹, Toshiaki Komata¹, Hiroki Oka¹, Qing Chang², Shogo Aoki³, Kazumasa Aoki⁴ (1. Tohoku Univ., 2. JAMSTEC, 3. AKita Univ., 4. Okayama Univ. of Sci.)

Keywords:Jadeitite, Forearc mantle wedge, Osayama Serpentinite Mélange, Zircon, Ca-amphibole

Jadeitites form in the forearc mantle wedge, and the jadeitite-hosted melange can stay within the mantle wedge for a considerable time. But how long are jadeitites retained in serpentinized mantle wedge environment? Our reevaluation of Osayama jadeitite suggests the possibility that jadeitite-hosted serpentinized mantle wedge can be retained for ~200 m.y..