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Dr. Jim Sample

Title: Professor
Degree: Ph.D., U.C. Santa Cruz
Specialty:  Low-Temperature Geochemistry, Marine Geology, Tectonics and Earth Science Education

Research Interests: My research focuses on fluid flow in the upper crust in active tectonic environments. I am interested in developing new ways to investigate the record of fluid flow in fault systems in order to understand the plumbing of fluid systems and how fluid-rock interactions affect rock properties over short and long time periods. The results of this research bears on the evolution of fluid circulation in the crust, deformation mechanisms and seismicity at active margins, redistribution of elements in the marine system, and perhaps on the evolution of life in extreme environments. My students, colleagues, and I investigate these processes using a variety of analytical techniques. Each project involves a substantial component of field mapping, rock characterization, and sample collection using the good old Brunton compass, high-precision mapping, and tools for field measurement of rock permeability. We characterize the cements and fabrics of the samples using petrography and image analysis including scanning electron microscopy and associated imaging techniques. We try to unravel fluid flow histories and the evolution of fluid sources by combining petrographic studies with mass spectrometry, focusing on the trace-element, stable, and radiogenic isotope geochemistry of precipitates left behind by fluids passing through the system. My current areas of research are carbonate cements and veins preserved in active faults in the Cascadia subduction zone, deformation bands and petroleum migration along the Newport- Inglewood fault zone in southern California, a Paleocene cold seep deposit (chemoherm) on the west side of the San Joaquin Valley, California, and fault systems in coarse-grained clastic rocks of the Colorado Plateau. In addition to basic scientific research, I am involved in projects to improve and increase Earth science education at the K-16 level.