02168nas a2200253   4500000000100000008004100001260001500042653002800057653002300085653002600108653002400134653002000158100001900178700001800197700002000215700001400235700002100249245010600270856007100376300001200447490000700459520143400466020001401900       2017                            d  c2017/07/0110aAtlantic deep sediments10aFe-Mn micronodules10aFe-Mn-(oxyhydr)oxides10aRare earth elements10aSeafloor mining1 aAmaya Menendez1 aRachael James1 aStephen Roberts1 aKate Peel1 aDouglas Connelly00aControls on the distribution of rare earth elements in deep-sea sediments in the North Atlantic Ocean  uhttp://www.sciencedirect.com/science/article/pii/S016913681630186X  a100-1130 v873 a<p> 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\textdegreeN that includes the deep Nares Abyssal Plain and the Canary and North America Basins. Total REY concentrations (ΣREY) range from 7.99 to 513ppm, and total concentrations of the heavy REY (Eu - Lu) range from 0.993 to 56.3ppm. 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 ΣREY (up to 3620ppm). REY concentrations are higher in micronodules that have a hydrogenous source, characterised by higher Fe/Mn, compared to micronodules that have a diagenetic source. The ΣREY 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 ~100km2, assuming removal of the upper 1m of sediment.</p>  a0169-1368