Particulate thallium fluxes in the northeast pacific

Abstract

Particulate fluxes of thallium in the northeast Pacific exhibit pronounced spatial gradients, which range over four orders of magnitude (3 X 10 −1 to 5.4 X 10 3 nmol m -2a −1) and show scavenging by both organic and inorganic processes. They are highly correlated (R=0.96) with POC fluxes, have have elevated rates in coastal upwelling waters, and decrease exponentially with depth. They also appear to be correlated with lateral fluxes of manganese (hydro)oxides off the continental shelf. These findings substantiate recent seawater measurements which indicate that metastable species of monovalent thallium are cycled through the marine biosphere as a potassium analogue, whereas thermodynamically stable trivalent thallium (TI (OH) 3) is scavenged by ferromanganese (hydro)oxides.