Structural and Fluid-Chemical Properties of Active Normal Faults

Pi和其他人最近的研究表明，流体在地壳变形中的作用是极其重要的，但人们对它的理解还不够完善。流体与活动变形带(断层)的相互作用是一个有益的研究领域，因为许多断层岩以流体包裹体的形式包含了在断裂过程中占主导地位的物理和化学条件的证据。这项研究将检验一个普遍的假设，即断裂带流体中溶解的二氧化碳的存在和分离在地震孕育中起着至关重要的作用。犹他州的两条活动正断层将被用作富二氧化碳流体和古流体压力梯度存在的试验点。此外，还将量化断裂带结构与流体通道的关系。这些结果将对我们理解断层启动和传播过程中的流体产生重大影响，并将增强对地震机制的理解。

Recent work by the PI's and others has shown that the role of fluids in the deformation of earth's crust is extremely important and yet imperfectly understood. The interaction of fluids with active deformation zones (faults) is a profitable area for research because many of the fault rocks contain evidence, in the form of fluid inclusions, for the physical and chemical conditions that prevailed during faulting. This study will test a general hypothesis that the presence and separation of dissolved CO2 in fault zone fluids plays a crucial role in earthquake generation. Two active normal faults in Utah will be used as test sites for the presence of CO2-rich fluids and paleo-fluid pressure gradients. In addition, the relationship between fault zone structure and fluid channels will be quantified. The results will have major impact and our understanding of fluids in fault initiation and propagation processes and will enhance understanding of earthquake mechanisms.