19-8. Geology, geochemistry and global context of deep-ocean marine minerals

Any true evaluation of global minerals must consider the marine realm. Marine minerals occur in every ocean basin, on both continental and oceanic crust; some are currently forming today, and some began forming 70 million years ago. The most well-known deep-ocean mineral deposits are ferromanganese crusts and manganese nodules (Hein and Koschinsky, 2014) composed mainly of iron and manganese oxides that accumulate trace metals sourced from seawater and porewaters over millions of years, and hydrothermal deposits composed mainly of metal sulfide minerals (Gartman et al., 2014) that accumulate over thousands of years at tectonic boundaries and intraplate hotspots. These deposits exhibit significant variability in extent and element composition across both timescales of formation, as well as spatially on local and global scales. In addition to manganese nodules, ferromanganese crusts, and seafloor sulfide minerals, other marine minerals that have generated interest include phosphorite deposits, found in open-ocean environments and continental margins, and rare-earth element rich marine muds in the deep ocean.  

Interest in marine minerals is increasing globally from government, private industry, and research entities. In addition to containing elements that may be economically valuable or critical to societal needs, these minerals may be used to provide insight into the formation of ancient marine mineral deposits now emplaced on land such as Volcanogenic Massive Sulfide (VMS) deposits. The deep oceans are difficult to access and many challenges remain for this research, including deposit mapping and characterization, interactions between minerals and the marine environment, and the development of technology for oceanographic mineral exploration. There is currently no mining of deep-ocean minerals, however increased delineation of resources and a clarifying regulatory regime suggests doing so may be viable within the next several years. Scientific understanding of these mineral resources is necessary to provide information to society as to the location, extent, manner of formation, and marine mineral extraction options and their potential consequences; as well as context for marine minerals in the global framework of mineral resources. 

We seek a postdoctoral scholar who can make a fundamental contribution to marine mineral research. Proposed work may use either archival samples (extensive USGS and other sample sets exist), or propose the collection of new samples, as feasible. Proposed work may focus in any of the following areas: (1) experimental studies regarding the environmental consequences of marine mineral extraction, (2) targeted speciation and extractability studies of marine critical minerals, (3) estimates of marine minerals within the context of global mineral resources, including terrestrial minerals, (4) statistical analyses of existing marine mineral datasets, (5) relating terrestrial and marine minerals in adjacent settings or (6) developing geophysical techniques to detect or study marine minerals. Other topics may be of interest. In particular, we welcome applications that cross disciplinary boundaries between marine science and geology, and applications that focus on the distribution, extent, or relevance of critical minerals in marine mineral deposits. Proposals that tie in the Earth MRI framework (Hofstra and Kreiner, 2020) are also welcome.

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

References:  

Gartman, A., Hannington, M., Jamieson, J.W., Peterkin, B., Garbe-Schönberg, D., Findlay, A.J., Fuchs, S., and Kwasnitschka, T. 2018. Boiling-induced formation of colloidal gold in black smoker hydrothermal fluids. Geology 46, 1, 39-42 

Gartman, A., and Hein, J.R. 2019. Mineralization at Oceanic Transform Faults and Fracture Zones. 105-118. In Transform Plate Boundaries and Fracture Zones, Elsevier doi: 10.1016/B978-0-12-812064-4.00005-0 

Hayes, S.M., McCullough, E.A., 2018. Critical minerals: A review of elemental trends in comprehensive criticality studies. Resources Policy. 59, 192-199. 

Hein, J.R. and Koschinsky, A., 2014. Deep-ocean ferromanganese crusts and nodules. In Holland, H.D. and Turekian, K.K. (eds.), Treatise on Geochemistry, Second Edition, v. 13, Chapter 11, p. 273-291, Oxford, Elsevier (http://dx.doi.org/10.1016/B978-0-08-095975-7.01111-6) 

Hofstra, A.H., and Kreiner, D.C., 2020, Systems-Deposits-Commodities-Critical Minerals Table for the Earth Mapping Resources Initiative: U.S. Geological Survey Open-File Report 2020–1042, 24 p., https://doi.org/10.3133/ofr20201042. 

Mizell, K., Hein, J. R., Lam, P. J., Koppers, A. A. P., & Staudigel, H. (2020). Geographic and oceanographic influences on ferromanganese crust composition along a Pacific Ocean meridional transect, 14 N to 14S. Geochemistry, Geophysics, Geosystems, 21, e2019GC008716  

Proposed Duty Station: Santa Cruz, CA 

Areas of PhD: Geology, earth science, marine geology, oceanography 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 Oceanographer, Research Chemist, Research Geophysicist. 

(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: Beverly Ledbetter, 916-278-9396, bledbetter@usgs.gov 

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