David is a Research Geologist with Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, CA. Since joining the USGS in 1992, he has worked on many topics in volcanology, tectonics of southern California, Nevada, and Arizona, groundwater in arid environments in southern CA, and characterization of a possible high-level radioactive waste repository site at Yucca Mountain, NV.
David has been studying the physical and geochemical characteristics of volcanic and sedimentary rocks since his bachelor’s degree. He applies geologic mapping (at many scales) and petrology (microscopy, whole-rock and electron microprobe geochemistry) to a wide variety of projects including (1) depositional and post-depositional processes that formed the rocks, (2) depositional history recorded in a sequence of deposits, (3) structural deformation of rocks through time, and (4) translation of the geologic processes and history that formed the rocks into distributions of hydrogeologic and thermo-mechanical properties used by modelers and land use planners.
David’s first 20 years with the USGS was working on site characterization of a possible high-level radioactive waste repository site in volcanic and sedimentary rocks at Yucca Mountain, Nevada, USA. He worked on detailed mapping of rocks exposed at the land surface and especially those penetrated in boreholes and tunnels. He led in the development of a detailed volcanological-based stratigraphy that was used as the foundation for the 3D site geologic framework model. His work on development of geologic properties that relate to hydrogeologic and thermo-mechanical properties (such as porosity and fractures) helped establish integrated and multi-scale modeling of the site characteristics.
David is currently working in the Mojave Desert, California, on groundwater investigations and structural deformation in the Eastern California Shear Zone, a zone of faults that accommodate motion of the North American and Pacific tectonic plates. His focus is on rocks that formed 2-25 million years ago with detailed studies of volcanic deposits (from lava flow, pyroclastic flow, and fallout tephra processes) and sedimentary deposits (from stream flow, avalanche, and aeolian process), and how these rocks were deformed to help build deep-time geologic frameworks for groundwater basins and earthquake hazards.
2012-present, Research Geologist, U.S. Geological Survey, Menlo Park, CA
2010-2012, Geologist, U.S. Geological Survey, Menlo Park, CA
1992-2010, Geologist, U.S. Geological Survey, Las Vegas, NV
1980-1992 (intermittently), faculty at Pasadena City College, CA, California State University Los Angeles, and Idaho State University, Pocatello.
Education and Certifications
Ph.D., Geology (with a focus on volcanology) UC, Santa Barbara, 1992
M.S., Geology, California State University, Los Angeles, 1984
B.S., Geology, California State University, Los Angeles, 1978
Affiliations and Memberships*
American Geophysical Union
Geological Society of America
International Association of Volcanology and Chemistry of the Earth’s Interior
Science and Products
Science and Products
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government