Dynamic Permeability in Deformation & Fluid Flow in Accretionary Prisms

吸积棱镜中ODP孔的地球化学和热异常表明幕式流体流动；远景钻探区的一些地震反射资料显示沿滑脱带存在空间分离的大振幅反射，可能提示存在富流体膨胀带。流体可能沿富泥断裂带在流体脉冲、位错、高渗透耦合系统中流动。为了验证这一概念，本项目将对动态渗透率或沉积物在变形过程中输送流体的瞬时能力进行初步实验研究。一个耦合在三轴电池上的恒定流量渗透率计将测量变形样品内恒定流量产生的压力差。实验将在中等低围压下的泥浆上进行，以模拟滑脱带或其他断层的条件，这些断层位于靠近吸积棱镜脚趾的可钻深度内。

Geochemical and thermal anomalies in ODP holes in accretionary prisms indicate episodic fluid flow; some seismic reflection data in prospective drilling areas show spatially separate, thigh-amplitude reflections along the decollement zone, perhaps suggestive of fluid rich dilatant zones. Fluids may flow along mud-rich fault zones in a coupled fluid-pulse, dislocation, high permeability system. In order to test this concept this project will conduct a pilot experimental study of dynamic permeability or the transient ability of sediments to transport fluids during deformation. A constant-flow rate permeameter coupled across a triaxial cell will measure pressure differences generated by constant flow within deforming samples. Experiments will be conducted on muds at moderately low confining pressures to simulate conditions in the decollement zone or other faults within drillable depths near the toe of the accretionary prism.