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USGS Mendenhall Postdoctoral Research Fellowship Program

17-33. Geophysical characterization of critical mineral and geothermal resources and processes in the western U.S.

For this Research Opportunity we seek candidates who will contribute much needed improvements to potential-field and electrical resistivity models currently being used to evaluate mineral and geothermal resources in the western U.S. We encourage research to identify and define areas favorable for mineral and geothermal resources, hydrothermal alteration, and subsurface fluid flow. Current areas of interest include: critical rare earth element (REE) mineral investigations in the southeast Mojave Desert, California; and critical lithium, tungsten, and geothermal resource investigations in the basins of the Owens River drainage system and the Salton Sea area, southern California. Geophysical studies are focused in the southeast Mojave Desert, which lies at the edge of the North American craton and hosts a world-class REE deposit at Mountain Pass, California and is the largest and only proven economic deposit in the U.S..  The Owens River drainage system contains one of the largest tungsten resources in the U.S., and the subsurface brine at Searles Lake has been mined for lithium. The Salton Sea is located along the San Andreas fault and is undergoing active deformation and hosts one of the largest lithium brine deposits in the U.S. and is also associated with a geothermal system.

The Mendenhall Fellow will conduct research and work collaboratively with geologists and geophysicists to produce one, two-, or three-dimensional geophysical models to improve existing or create new interpretations of the mineral or geothermal resources of the western U.S. The researcher will be expected to develop innovative interpretations of these data. Fundamental questions to be addressed include: What is the geometry of subsurface structures controlling the mineral or geothermal resource? How is alteration related to the mineral or geothermal system? What is the nature and distribution of the mineralization or heat source? How does interaction of active tectonics, magmatism, and hydrologic processes affect the size and location of the mineral or geothermal system? How can we more effectively use geophysical surveys to identify areas with potential mineral and geothermal resources and better incorporate these results in assessments? Can geophysical methods identify flow paths for groundwater brines?

The postdoctoral researcher will benefit from a wealth of available materials and datasets. For example, a new high-resolution airborne gravity gradiometry, magnetic, radiometric, and lidar survey; in addition, a detailed land-based gravity survey and physical property data of the REE deposit at Mountain Pass, California are available. Lithium, a critical element present in elevated concentrations can be found in geothermal brines and other basin brines across the western U.S. One of the largest Li resources is associated with the Salton Sea geothermal system in southern California, but other known basinal brines are found at Searles Lake and other evaporative lake basins throughout the Great Basin.  Mountain Pass, Salton Sea, and the western Great Basin are a one-day drive southeast of Menlo Park, CA and are accessible year-round, making them both good logistical as well as significant scientific targets. The USGS has been conducting potential-field and electromagnetic studies in the southeast Mojave Desert, Salton Sea, and western Great Basin areas for several years, and new gravity and magnetic datasets are available in these areas. Outside of these areas, regional gravity and magnetic data are available throughout the western U.S.

Interested applicants are strongly encouraged to contact the advisors below early in the application process to discuss project ideas.

Proposed Duty Station: Menlo Park, CA

Areas of Ph.D.: Geophysics (or geology) with a focus on potential field (gravity and magnetic) and/or electromagnetic methods (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).

Qualifications: Applicants must meet the following qualifications: Research Geophysicist, Research Geologist (This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)

Research Advisor(s): David Ponce (650) 329-5314,; Jonathan Glen (650) 329-5282,; Jared Peacock (650)329-4833,; Victoria Langenheim (650) 329-5313,; Lisa Stillings, (775) 784-5803,; and David John, (650) 329-5424,

Human Resources Office Contact: Yumi Sakakibara,, 916-278-9384

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U.S. Department of the Interior, U.S. Geological Survey
URL: Ponce.htm
Direct inquiries to Rama K. Kotra at
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Last modified: 17:08:43 Wed 14 Nov 2018
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