Experimental investigation of reaction-induced shear instability at high pressure

2016 Fiscal Year Final Research Report

• Project/Area Number: 25247089
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Kyushu University
• Principal Investigator: KUBO TOMOAKI 九州大学, 理学研究院, 准教授 (40312540)
• Co-Investigator(Kenkyū-buntansha): 肥後 祐司 公益財団法人高輝度光科学研究センター, その他部局等, 研究員 (10423435) ; 上原 誠一郎 九州大学, 理学(系)研究科(研究院), 助教 (70158773) ; 金嶋 聰 九州大学, 理学(系)研究科(研究院), 教授 (80202018) ; 加藤 工 九州大学, 理学(系)研究科(研究院), 教授 (90214379)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 深発地震 / 変形実験 / 高圧実験 / AE測定 / 放射光X線その場観察 / 蛇紋石 / 脱水反応

Outline of Final Research Achievements

Serpentine dehydration has been one of the important candidates for triggering intermediate-depth earthquakes. In order to examine this topic, we developed an AE monitoring system for high-pressure reaction-deformation processes combined with Deformation-DIA apparatus and synchrotron monochromatic X-ray. We applied this technique to investigate shear instability during antigorite dehydration in pure shear up to ~7 GPa and ~600°C . Almost no AEs were detected within the antigorite samples during deformation and syndeformational dehydration. Instead, we detected some AEs outside the sample at around the boundaries of cylindrical parts. Our results suggest that dehydration of antigorite do not directly trigger shear instability at high pressures at least in pure shear under drained condition.

Free Research Field

鉱物物理学