2022 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 17 - Sep 19, 2022新潟大学 五十嵐キャンパス
2022 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 17 - Sep 19, 2022新潟大学 五十嵐キャンパス
[R7-05]The mechanism of bipyramidal quartz formation in Kuroko deposits[Presentation award entry]
*Jumpei Sugioka1, Ryoichi Yamada1, Atsushi Okamoto1(1. Tohoku Univ. Env.)
Keywords:
Quartz,Silica,Kuroko deposits,Submarine hydrothermal deposits,Hydrothermal experiments
We analyzed Kuroko ore specimens and conducted hydrothermal experiments to discuss the mechanism of bipyramidal quartz formation in Kuroko deposits. Fluid inclusion microthermometry revealed that the bipyramidal quartz in Kuroko formed in fluid at about 300℃. Hydrothermal experiments revealed that the bipyramidal quartz formed by phase transition from amorphous silica. The bipyramidal quartz is thought to have formed by supersaturation of silica in a fluid maintained at high temperature in the stockworks in the subsurface of the Kuroko deposits.