Hydrothermal scavenging on the Juan de Fuca Ridge: 23OThxs, 10Be, and REEs in ridge-flank sediments

Sulfur, sulfides, oxides and organic matter aggregated in submarine hydrothermal plumes at 9°50′N East Pacific Rise

“…Part of this lower enrichment is potentially due to the fact that uptake of REEs by Fe oxyhydroxides is a continuous scavenging process. For this reason, the anticipated REE/Fe ratios of hydrothermal plume particulates are also anticipated to increase progressively as plume particles are dispersed through the water column and into the underlying sediments, as was the case for particulate Fe concentrations (Ruhlin and Owen, 1986;Owen and Olivarez, 1988;Olivarez and Owen, 1989;German et al, 1990German et al, , 1997Edmonds and German, 2004). Consistent with those earlier studies, the trends for our samples of particulate REE versus particulate Fe also show a marked positive curvature ( Fig.…”

Formation of Thetis Deep metal-rich sediments in the absence of brines, Red Sea

“…Related sulfide chimneys, mounds and sediments contain generally less REEs than the nearby marine sediments (Courtois and Clauer, 1980;Clauer et al, 1984;Marchig et al, 1986;German et al, 1995German et al, , 1997, but the Fe-oxi-hydroxides are enriched in REEs relative to sulfides due to particle-surface adsorption processes and/or direct co-precipitation of Fe-rich phases (e.g., Fleet, 1984;Mills et al, 1993;Mills and Elderfield, 1995;Pichler and Veizer, 1999). For instance, oxides of active and relict chimneys (26°N Mid-Atlantic Ridge) yield a typical REE hydrothermal signature, with concentrations that are two orders of magnitude higher than those of the associated sulfide minerals (e.g., Mills et al, 2001).…”

Geochemistry and morphology of metalliferous sediments and oxyhydroxides from the Endeavour segment, Juan de Fuca Ridge

“…''Fallout'' sediments, thus, can provide a record of the dispersal patterns and processes taking place within the plumes. The composition of sediments is further modified by post-depositional reactions such as oxidation/ dissolution and scavenging (Ruhlin and Owen, 1986;Feely et al, 1987;German et al, 1997).…”