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ID 34736
本文ファイル
著者
Takahashi, Miki
Uehara, Shin-Ichi
Mizoguchi, Kazuo
Shimizu, Ichiko
Okazaki, Keishi
Masuda, Koji
NDC
地球科学・地学・地質学
抄録(英)
Shear-sliding tests were conducted on serpentine (antigorite) gouge to understand the rheology of serpentine-bearing faults. The experiments were carried out using a constant confining pressure (100 MPa), a constant pore water pressure (30 MPa), and a range of temperatures (from room temperature to 600 degrees C). The transient response in frictional behavior following stepwise changes in the slip velocity were documented at each temperature. Slip rates varied between 0.0115 and 11.5 mu m/s. Both the general level of frictional strength and the transient responses changed drastically at around 450 degrees C. As the temperature increased from 400 degrees C to 450 degrees C, the strength of antigorite rose sharply. The transient response also indicated a change in the mode of deformation from flow-type behavior at temperatures below 400 degrees C to frictional behavior (stick-slip) at temperatures above 450 degrees C-500 degrees C. Although only a limited volume of serpentine was involved in the dehydration reaction, X-ray diffraction analyses and scanning electron microscopy observations showed that forsterite had nucleated in the experimental products at the higher temperatures that were associated with frictional behavior. Submicron-sized, streaky forsterite masses in shear-localized zones may be evidence of shear-induced dehydration that caused strengthening and embrittlement of the gouge. Although antigorite rheology is complicated, the subsequent change in friction coefficient per order-of-magnitude change in sliding velocity increased with both increasing temperature and decreasing velocity, implying that a possible flow mechanism of intragranular deformation became activated.
掲載誌名
Journal of Geophysical Research-Solid Earth
116巻
開始ページ
B10405
出版年月日
2011
出版者
American Geophysical Union
ISSN
0148-0227
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
publisher
権利情報
(c) 2011 by the American Geophysical Union.
関連情報URL
部局名
理学研究科