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.
