The effect of particulate dissolution on the neodymium (Nd) isotope and Rare Earth Element (REE) composition of seawater

Overview of the mechanisms that could explain the ‘Boundary Exchange’ at the land–ocean contact

“…Batch experiments or sequential leaching slightly illuminated the processes by confirming that a fraction of the lithogenic material can be dissolved, releasing some of the elements it contains and contributing to balance their isotopic composition [29][30][31][32]51]. These experiments also showed that secondary phases are rapidly formed, scavenging a large part of most of the released species.…”

“…However, because seawater is close to saturated or supersaturated with respect to many mineral phases, much of the chemical input into seawater from atmospheric or riverine transported particulate material dissolution should be readily precipitated as secondary mineral, consistent with the 'Boundary Exchange' hypothesis. This could affect the net element input flux, but not so clearly its isotopic composition and the impact of this composition on the local seawater [29][30][31][32]. Precise flux estimates will depend on a comprehensive understanding of processes governing particle-solution exchanges, opening a large field for further researches.…”

Neodymium isotopic characterization of Ross Sea Bottom Water and its advection through the southern South Pacific

“…2, Table S1), which at other stations and in the South Atlantic carries an isotope signature of ε Nd = ∼ −8 to −9 . The station is located above the ridge flank and we therefore suggest that the radiogenic bottom water ε Nd at this site is caused by boundary exchange with the basaltic rocks of the ridge (Lacan and Jeandel, 2005;Rickli et al, 2010;Pearce et al, 2013).…”

Lead isotope exchange between dissolved and fluvial particulate matter: a laboratory study from the Johor River estuary

“…The mechanism for this isotope exchange was proposed as contemporaneous dissolution and precipitation into secondary minerals [4,[12][13][14]. That suggested mechanism for Sr isotopes might not be plausible for Pb as the concentration for Pb in seawater is generally in the pico-molar region (e.g.…”