Controls of Gouge Heterogeneity on Cyclic Reactivation of Fault-Valve Systems

IF 4.6 1区地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Geophysical Research Letters Pub Date : 2025-07-25 DOI:10.1029/2025GL115092

Zhen Zhong, Zheye Song, Bo Li, Derek Elsworth, Yunjin Hu, Fengshou Zhang, Zhiyuan Chen

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Abstract

Fault zones are inherently heterogeneous and exert significant impacts on fluid injection-induced activities. We conducted Low-velocity shear experiments on homogeneous (HM) and layered (LM) clay-quartz mixtures representing gouge heterogeneity under double direct-shear and constant fluid injection. Cyclic fault-valve is activated in LM faults when the clay content is ≥50%, while it is absent in HM faults. A segmental layer of low-permeability clay perpendicular to the flow direction acts as a fault-valve, causing cyclic build-up then dissipation in pore pressure, hence influencing the magnitude of shear stress drop and sliding distance associated with seismic magnitudes. Recovered seismic moments from individual fault-valve cycles are bounded by the maximum seismic moment $M_{0}^{\max} = \frac{c}{2 (1 - c)} G ∆ V^{'}$ when a pre-stress coefficient c ranges 90–99%. This study highlights the role of spatial distributions in pore pressure as controlled by gouge compositions and spatial heterogeneity on slip stability, and verifies the applicability of $M_{0}^{\max} - ∆ V^{'}$ relation to fault-valve systems.

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断层泥非均质性对断层阀系统循环再激活的控制

断裂带本质上是不均匀的，对流体注入活动有重要影响。在双直剪和恒定流体注入条件下，对均质（HM）和层状（LM）粘土-石英混合物进行了低速剪切实验。当粘土含量≥50时，LM断层启动循环断层阀%, while it is absent in HM faults. A segmental layer of low-permeability clay perpendicular to the flow direction acts as a fault-valve, causing cyclic build-up then dissipation in pore pressure, hence influencing the magnitude of shear stress drop and sliding distance associated with seismic magnitudes. Recovered seismic moments from individual fault-valve cycles are bounded by the maximum seismic moment M 0 max = c 2 ( 1 − c ) G ∆ V ′ ${M}_{0}^{\max }=\frac{c}{2(1-c)}G\mathit{{\increment}}{V}^{\mathit{\prime }}$ when a pre-stress coefficient c ranges 90–99%. This study highlights the role of spatial distributions in pore pressure as controlled by gouge compositions and spatial heterogeneity on slip stability, and verifies the applicability of M 0 max − ∆ V ′ ${M}_{0}^{\max }-\mathit{{\increment}}{V}^{\mathit{\prime }}$ relation to fault-valve systems.

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来源期刊

Geophysical Research Letters 地学-地球科学综合

CiteScore

9.00

自引率

9.60%

发文量

1588

审稿时长

2.2 months

期刊介绍： Geophysical Research Letters (GRL) publishes high-impact, innovative, and timely research on major scientific advances in all the major geoscience disciplines. Papers are communications-length articles and should have broad and immediate implications in their discipline or across the geosciences. GRLmaintains the fastest turn-around of all high-impact publications in the geosciences and works closely with authors to ensure broad visibility of top papers.