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Pacific Coastal and Marine Science Center

Pacific EEZ Minerals

Photographs of manganese nodules from the Cook Islands EEZ.

Photographs of example Cook Islands manganese nodules from “Critical metals in manganese nodules from the Cook Islands EEZ, abundances and distributions,” Ore Geology Reviews v.68 (2015), by Hein and others, online at doi:10.1016/j.oregeorev.2014.12.011.

Pacific EEZ Minerals Study

Principal Investigator: James R. Hein

Little is known about the resource potential of the vast mineral deposits that occur within the 200 nautical mile Exclusive Economic Zone (EEZ) of the United States. The U.S. EEZ encompasses 3.4 million square nautical miles, an area about 20% greater than the land area of the U.S. Quantitative information about U.S. EEZ resources is essential in order for the Federal and State governments to make informed decisions about:

  1. competitive land(sea)-use issues,
  2. outer continental-margin boundary negotiations,
  3. contaminant issues, and
  4. energy, mineral, and biologic resources potential, including homeland security concerns of self sufficiency in energy and strategic and critical minerals.


The goals of the Pacific EEZ Minerals Study are to

  1. continually assess the state-of-knowledge of the mineral resources and associated environmental issues within the EEZs of Pacific islands of U.S. interest and elsewhere in the global ocean;
  2. analyze and synthesize existing published USGS and other compatible data;
  3. compile, analyze, and make available unpublished USGS data;
  4. collect new data for existing samples if warranted to produce more comprehensive and integrated USGS reports;
  5. collect new samples and data from ships of opportunity for seabed mineral deposits if dedicated cruises are not funded;
  6. provide marine minerals resource data on critical and strategic metals needed for high/emerging-tech, green-tech, energy, and military applications;
  7. provide value-added products based on prior field programs and existing data;
  8. provide liaison participation and expertise on marine mineral issues to national and international organizations, institutions, and agencies;
  9. maintain comprehensive knowledge of global activities concerning marine minerals; and
  10. provide outreach activities directed to education on EEZ and global minerals and associated environmental issues.

Seafloor Massive Sulfide Alteration Study

Principal Investigator: Amy Gartman

Interest in mining seafloor massive sulfides (SMS), which occur as a result of hydrothermal activity in the global ocean, is increasing and will likely begin in earnest within the next several years. The geochemical and environmental implications of this exploitation have not been constrained. The mining of SMS deposits will likely create a new class of abundant micron and sub-micron sized metal sulfide particles. These new particulates may potentially be more reactive than naturally occurring particles, with regard to oxidation and microbial colonization. This Mendenhall Postdoctoral project will evaluate the local-to-global geochemical consequences of the alteration of sulfide particles likely to occur as a result of SMS mining relative to similar particles emitted from natural hydrothermal systems, and will consider potential environmental perturbations due to SMS resource extraction.


The goals of this project are to:

  1. characterize the mineralogy, surface chemistry, and the dissolution/oxidation rate of newly formed hydrothermal precipitates, relative to crushed particles likely to be created through mining;
  2. characterize changes in pH and inorganic carbon chemistry as a result of the dissolution/oxidation of these minerals;
  3. characterize the effect of microbial activity on the rate of dissolution/oxidation of these particles;
  4. evaluate the effect of microbial growth on the carbon budget in these systems; and
  5. use this data to assess the potential spatial and temporal impacts of mined particles on ocean chemistry.
Recent Publications

Critical metals in manganese nodules from the Cook Islands EEZ, abundances and distributions - Ore Geology Reviews v.68, 2015

Persistence of deeply sourced iron in the Pacific Ocean - Proceedings of the National Academy of Sciences v.112, 2015

Discriminating between different genetic types of marine ferro-manganese crusts and nodules based on rare earth elements and yttrium - Chemical Geology v.381, 2014

Deep-Ocean Ferromanganese Crusts and Nodules - Treatise on Geochemistry v.13: Geochemistry of Mineral Deposits, 2014

Layered Hydrothermal Barite-Sulfide Mound Field, East Diamante Caldera, Mariana Volcanic Arc - Economic Geology v.109, 2014

Molecular controls on Cu and Zn isotopic fractionation in Fe-Mn crusts - Earth and Planetary Science Letters v.396, 2014

See all publications


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