气候变化领域集成服务门户(CCPortal): Influence of Effective Stress and Pore Fluid Pressure on Fault Strength and Slip Localization in Carbonate Slip Zones

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DOI	10.1029/2020JB019805
	Influence of Effective Stress and Pore Fluid Pressure on Fault Strength and Slip Localization in Carbonate Slip Zones
	Rempe M.; Di Toro G.; Mitchell T.M.; Smith S.A.F.; Hirose T.; Renner J.
发表日期	2020
ISSN	21699313
卷号	125 期号:11
英文摘要	The presence of pressurized fluids influences the mechanical behavior of faults. To test the roles of normal stress and fluid pressure on shear strength and localization behavior of calcite gouges, we conducted a series of rotary-shear experiments with pore fluid pressures up to 10.5 MPa and difference between normal stress and fluid pressure up to 11.2 MPa. Calcite gouges were sheared for displacements of 0.3 m to several meters at slip rates of 1 mm/s and 1 m/s. Drainage conditions in experiments were constrained from estimates of the hydraulic diffusivity. Gouges were found to be drained at 1 mm/s, but possibly partially undrained during sliding at 1 m/s. Shear strength obeys an effective-stress law with an effective-stress coefficient close to unity with a friction coefficient of ~0.7 that decreases to 0.19 due to dynamic weakening. The degree of comminution and slip localization constrained from experimental microstructures depends on the effective normal stress. Slip localization in calcite gouges does not occur at low effective normal stress. The presence of pore fluids lowers the shear strength of gouges sheared at 1 mm/s and causes an accelerated weakening at 1 m/s compared to dry gouges, possibly due to enhanced subcritical crack growth and intergranular lubrication. Thermal pressurization occurs only after dynamic weakening when friction is generally low and relatively independent of normal stress and therefore unaffected by thermal pressurization. The experimental results are consistent with the view that the presence of pressurized fluid in carbonate-bearing faults can facilitate earthquake nucleation. ©2020. The Authors.
英文关键词	calcite gouges; effective-pressure law; microstructures; rotary-shear experiments; seismic slip rates; strain localization
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187487
作者单位	Institute for Geology, Mineralogy and Geophysics, Ruhr-Universitaet Bochum, Bochum, Germany; Departimento die Geoscienze, Università degli Studi di Padova, Padua, Italy; Instituti di Geofisica e Vulcanologia, INGV, Rome, Italy; Rock and Ice Physics Laboratory and SeismoLab, Department of Earth Sciences, University College London, London, United Kingdom; Department of Geology, University of Otago, Dunedin, New Zealand; Kochi Institute for Core Sample Research, JAMSTECKochi, Japan
推荐引用方式 GB/T 7714	Rempe M.,Di Toro G.,Mitchell T.M.,et al. Influence of Effective Stress and Pore Fluid Pressure on Fault Strength and Slip Localization in Carbonate Slip Zones[J],2020,125(11).
APA	Rempe M.,Di Toro G.,Mitchell T.M.,Smith S.A.F.,Hirose T.,&Renner J..(2020).Influence of Effective Stress and Pore Fluid Pressure on Fault Strength and Slip Localization in Carbonate Slip Zones.Journal of Geophysical Research: Solid Earth,125(11).
MLA	Rempe M.,et al."Influence of Effective Stress and Pore Fluid Pressure on Fault Strength and Slip Localization in Carbonate Slip Zones".Journal of Geophysical Research: Solid Earth 125.11(2020).