S41. Geochronology of mineralizing systems

The U.S. Geological Survey Mineral Resources Program (MRP) provides unbiased science to increase understanding of ore formation and undiscovered mineral resource potential. Understanding the timing of geologic processes is essential for establishing the geologic framework of ore-mineralizing systems. High precision geochronology provides absolute time limits on processes—such as volcanic eruptions, emplacement of intrusions, fluid infiltration, faulting, and sedimentation—that are essential for mineral resource assessments.

To further our core mission, we seek individual(s) to conduct research focused on the development and application of isotope geochronology. Specifically, we seek research proposals focused on using either the ⁴⁰Ar/³⁹Ar or U-Pb TIMS (or other radiogenic geochronometers) to address problems broadly related to the understanding of mineralizing systems.

The current United States import reliance for many strategic and critical minerals¹ has generated renewed interest in better understanding domestic mineral resources and mineral resource potential².  In many parts of the United States, the lack of high-precision geochronology and other isotopic and geochemical data prevent advances in understanding the geologic and tectonic framework favorable to localizing specific mineral resources.  This research opportunity provides broad latitude in method development and application of geochronology to understanding local and regional-scale processes controlling mineralizing systems.  We are particularly interested in the acquisition of geochronological data and its integration into regional geologic and geochemical frameworks.

The MRP supports a number of projects that combine high-precision geochronology with detailed mineral characterization, rock geochemistry, and field relations to provide better geologic context on the occurrence and distribution of mineralizing systems³.  It is anticipated that research proposals are aligned along common goals with one or more of these projects.  State-of-the-art clean laboratories, extraction lines, and mass spectrometers are currently operational and available for the research.  Potential research topics may include (but are not limited to) the following active areas of MRP research:

---Geochronology and mineral resource potential for rare earth element (REE) mineralization.  For example, are there temporal and spatial patterns on the distribution of carbonatites in the alkaline province of Wyoming and Montana?  Is there geochronological evidence for any tectonic control(s) on REE mineralization? 

---High precision geochronology of layered mafic intrusions.  How can high-precision geochronology be used to provide evidence for mechanisms of layered mafic magma emplacement?  Can geochronology of layered intrusions be used in models of mineral resource assessments? 

---High precision geochronology of sources and sinks of lithium within the Basin and Range.  Can lithium in basin sediments be traced to specific volcanic sources?  Are lithium-bearing rhyolites erupted over discrete time intervals?

---Timing and source regions of base and precious metals associated with epithermal systems.  What is the time scale and nature of the mantle lithosphere associated with mineralization?  Can geochronology of alteration be used as a temporal indicator for mineralization?

Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas.

References:

¹U.S. Geological Survey, 2019, Mineral commodity summaries 2019: U.S. Geological Survey, 200 p., https://doi.org/10.3133/70202434.

² https://www.commerce.gov/news/reports/2019/06/federal-strategy-ensure-secure-and-reliable-supplies-critical-minerals

³https://www.usgs.gov/energy-and-minerals/mineral-resources-program/science

Proposed Duty Station: Lakewood, CO

Areas of PhD: Geochronology, petrology, economic geology, mineralogy or related fields (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 qualifications for: Research Geologist or Research Chemist

(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.)

Human Resources Office Contact: Audrey Tsujita, 916-278-9395, atsujita@usgs.gov