The application of failure mode diagrams for exploring the roles of fluid pressure and stress states in controlling styles of fracture-controlled permeability enhancement in faults and shear zones
The application of failure mode diagrams for exploring the roles of fluid pressure and stress states in controlling styles of fracture-controlled permeability enhancement in faults and shear zones
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DOI：
10.1111/j.1468-8123.2010.00281.x
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发表时间：
2010-05-01
期刊：
影响因子：
1.7
通讯作者：
Cox, S. F.
中科院分区：
文献类型：
--
作者：
Cox, S. F.
与断层和剪切带变形过程相关的渗透性增强在促进地壳流体储层之间的流体再分配中起着关键作用。特别是在高流体通量的热液系统中，孔隙控制的渗透率可能相对较短，除非它通过持续的变形反复再生。在孔隙流体因子和差应力空间中的破坏模式图，这里被称为Σ-Σ破坏模式图，为分析流体压力和应力状态如何驱动断层和剪切带变形期间的破坏、相关渗透率增强和脉样式提供了有力的工具。在孕震区的断层阀行为期间，破裂事件之间的孔隙流体因子、差应力和断层内聚强度的相对恢复率影响断层和剪切带中脉纹和相关的、受断层控制的渗透率增强的样式。富脉断层带的例子被用来说明如何限制，不仅在故障时的流体压力和应力状态，而且在故障和短暂的渗透性增强断层和剪切带的流体加压和加载路径。这提供了关于在断层瓣膜循环期间何时可以形成各种类型静脉的见解。故障模式图的使用还提供了有关最佳定向故障和错误定向故障作为水力传导结构的相对作用的见解。该分析突出了流体压力和加载速率之间的竞争，在驱动故障和重复渗透率再生的控制，热液系统的动态。
Permeability enhancement associated with deformation processes in faults and shear zones plays a key role in facilitating fluid redistribution between fluid reservoirs in the crust. Especially in high fluid flux hydrothermal systems, fracture-controlled permeability can be relatively short-lived, unless it is repeatedly regenerated by ongoing deformation. Failure mode diagrams in pore fluid factor and differential stress space, here termed lambda-sigma failure mode diagrams, provide a powerful tool for analysing how fluid pressure and stress states drive failure, associated permeability enhancement and vein styles during deformation in faults and shear zones. During fault-valve behaviour in the seismogenic regime, relative rates of recovery of pore fluid factor, differential stress and fault cohesive strength between rupture events impact on styles of veining and associated, fracture-controlled permeability enhancement in faults and shear zones. Examples of vein-rich fault zones are used to illustrate how constraints can be placed, not just on fluid pressure and stress states at failure, but also on the fluid pressurization and loading paths associated with failure and transitory permeability enhancement in faults and shear zones. This provides insights about when, during the fault-valve cycle, various types of veins can form. The use of failure mode diagrams also provides insights about the relative roles of optimally oriented faults and misoriented faults as hydraulically conductive structures. The analysis highlights the dynamics of competition between fluid pressures and loading rates in driving failure and repeated permeability regeneration in fracture-controlled, hydrothermal systems.