Controls on the distribution of rare earth elements in deep-sea sediments in the North Atlantic Ocean

Menendez, Amaya; James, Rachael A.; Roberts, Stephen; Peel, Kate; Connelly, Douglas. 2017 Controls on the distribution of rare earth elements in deep-sea sediments in the North Atlantic Ocean. Ore Geology Reviews, 87. 100-113. https://doi.org/10.1016/j.oregeorev.2016.09.036

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© 2016 Elsevier B.V. This is the author’s version of a work that was accepted for publication in Ore Geology Reviews. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version will be published in Ore Geology Reviews
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Abstract/Summary

Deep-sea sediments can contain relatively high concentrations of rare earth elements and yttrium (REY), with a growing interest in their exploitation as an alternative to land-based REY resources. To understand the processes that lead to enrichment of the REY in deep-sea sediments, we have undertaken a detailed geochemical study of sediments recovered from the Atlantic Ocean, on a transect along ~24 ?N that includes the deep Nares Abyssal Plain and the Canary and North America Basins. Total REY concentrations (?REY) range from 7.99 to 513 ppm, and total concentrations of the heavy REY (Eu - Lu) range from 0.993 to 56.3 ppm. REY concentrations are highest in slowly accumulating pelagic red clays, especially in samples that contain ferromanganese micronodules. Factor analysis reveals that hydrogenous Fe- and Mn-(oxyhydr)oxides are the primary REY carrier phase in the red clays. In situ analysis of individual micronodules confirms that they have high ?REY (up to 3620 ppm). REY concentrations are higher in micronodules that have a hydrogenous source, characterized by higher Fe/Mn, compared to micronodules that have a diagenetic source. The ?REY content of North Atlantic deep-sea sediments is ~4 times lower than in Pacific deep-sea sediments. We calculate that the area of seafloor required to extract ~10% of the global annual REY demand is ~100 km2, assuming removal of the upper 1m of sediment.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.oregeorev.2016.09.036
ISSN:	0169-1368
Additional Keywords:	Rare earth elements, Fe-Mn micronodules, Atlantic deep sediments, seafloor mining, Fe-Mn-(oxyhydr)oxides
Date made live:	28 Sep 2016 10:49 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/514634

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.oregeorev.2016.09.036

ISSN:

0169-1368

Additional Keywords:

Rare earth elements, Fe-Mn micronodules, Atlantic deep sediments, seafloor mining, Fe-Mn-(oxyhydr)oxides

Date made live:

28 Sep 2016 10:49 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/514634