9526710 Morgan The PI proposes to develop an experimental capability to measure electrokinetic streaming potential data of the cross-coupling coefficient (volts per pressure difference) and the associated approximation of the water/mineral surface potential at in situ P/T conditions for whole rock samples. Most of the values presently available were obtained at ambient conditions or on crushed rock at elevated temperatures. These will be the first streaming potential data to be collected on a suite of earth materials in contact with varying chemical solutions at elevated P/T conditions of the earth's crust. These data are essential for understanding the role of water in subsurface processes, and will have many engineering and environmental applications related to ground water monitoring, oil-well pumping patterns, electroseismic effects and possibly as electromagnetic earthquake precursors, as well as scientific applications in fracture mechanics, seismic attenuation, electrical impedance modeling. ***