Description of the Research Opportunity
Ultramafic terranes are the primary sources of several critical mineral commodities, including cobalt, chromium, nickel, and platinum group elements. The supply chains of these commodities are at increasing risk of disruption owing to concentration of production as well as demand driven by the energy transition technologies (e.g., electric vehicle batteries). Furthermore, serpentinization processes in ultramafic rocks are actively being investigated for their potential to sequester carbon dioxide (Kelemen and others, 2020) and produce geological hydrogen resources (Hand, 2023). Robust assessments of mineral resources, carbon sequestration, and hydrogen resource potential depend upon detailed geochemical, mineralogical, and microstructural characterization of unaltered protoliths (e.g., peridotite), hydrothermally altered serpentinite, and chemical weathering products (e.g., nickel laterites) present in ultramafic terranes. This opportunity focuses on characterizing ultramafic terranes in the United States and Puerto Rico as geological analogues for determining the fundamental parameters (e.g., area, volume, grade, tonnage, mineralogy; Berger and others, 2011) needed to assess multi-resource potential of nickel laterites, their associated parent rocks, and likely waste material.
Nickel laterites host about 60% of global identified resources of nickel (McRae, 2023) and an increasing share of production; however, development of laterite resources is fraught with environmental challenges (Tan and others, 2023). Because nickel laterites form in tropical latitudes, the sparsity of data in areas with thick vegetation and consistent cloud cover makes assessment of resource potential difficult. Fundamental questions remain regarding the spatial variation of ore grade, geochemistry, mineralogy, and texture of supergene deposits and relationships to their parent lithologies (Marsh and others, 2013). Addressing these questions involves working at multiple scales, encompassing micro-scale analytical techniques (LA-ICPMS, EPMA, SEM, and XRD), as well as spectroscopic studies combining field, laboratory and/or remote sensing methods as appropriate. Geospatial modeling workflows require deriving mappable proxies from structural, lithological, geophysical, remote sensing, and topographic data and applying machine learning techniques for image classification and feature delineation.
The ideal candidate is a broadly trained geoscientist experienced in micro-analytical methods, image processing, and remote sensing techniques. Domain expertise with ultramafic rocks and mineralogy is preferable though not an absolute requirement. We therefore seek candidates with interest in economic geology, geospatial analysis, and machine learning applications.
Possible project ideas include but are not limited to 1) comparing mineral resource and environmental aspects of nickel laterites in Oregon, California, and Puerto Rico to mined deposits; 2) characterizing latitudinal changes in remote sensing signatures of laterites and associated vegetation; 3) investigating structural and microstructural controls on secondary mineralization; 4) discerning the characteristics that localize nickel laterite development in mineralized terranes and nonmineralized areas; or 5) examining spectral characteristics of supergene chemical weathering deposits in tropical environments.
Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas.
References:
Berger, V.I., Singer, D.A., Bliss, J.D., and Moring, B.C., 2011, Ni-Co laterite deposits of the world-database and grade and tonnage models: U.S. Geological Survey Open-File Report 2011-1058.
Hand, Eric, 2023, Hidden hydrogen: Science, v. 379, doi: 10.1126/science.adh1460.
Kelemen, P.B, McQueen, N., Wilcox, J., Renforth, P., Dipple, G., and Vankeuren, A.P., 2020, Engineered carbon mineralization in ultramafic rocks for CO2 removal from air: Review and new insights: Chemical Geology, v. 550, https://doi.org/10.1016/j.chemgeo.2020.119628.
Marsh, Erin, Anderson, Eric, and Gray, Floyd, 2013, Nickel-cobalt laterites—A deposit model, chap. H of Mineral deposit models for resource assessment: U.S. Geological Survey Scientific Investigations Report 2010–5070–H, 38 p., http://pubs.usgs.gov/sir/2010/5070/h/.
McRae, M.E., 2023, Nickel in Mineral commodity summaries 2023: U.S. Geological Survey, 210 p., https://doi.org/10.3133/mcs2023.
Tan, R., Sijabat, D.M., and Irwandi, J., 2023, To mine EV minerals, industry turns to dangerous refinery technology: Washington Post, https://www.washingtonpost.com/world/interactive/2023/ev-nickel-refinery-dangers/.
Proposed Duty Station(s)
Reston, Virginia
Areas of PhD
Geoscience, geology, mineralogy, petrology, soil science, 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 one of the following qualifications: Research Geologist, Research Geographer, Research Physical Scientist
(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.)
