Papers

Two studies published by Jule Middleton documenting the rates, sensitivities, and barium-isotopic consequences of ion exchange in barite. The first paper investigated how fast and how much ion exchange affected the isotope composition of barium in barite–fluid systems. We did this by performing laboratory experiments under marine-relevant conditions. The main findings are that ion exchange…

What controls the distribution of dissolved barium in the Arctic? This is the question we tried to answer in a recent study led by Laura Whitmore. The study integrates measurements of dissolved and particulate barium and barium isotope compositions measured on samples collected during four GEOTRACES Arctic expeditions in 2015—GN01, GN02, GN03, and GN04 (HLY1502,…

Are you interested in productivity, paleoceanography, or proxies, but don’t know where to start? Maybe you have a question about a specific bioactive element and want to find out if it has already been addressed? Or perhaps you just want to look at cartoons summarizing modern marine micronutrient cycling? If any of these apply to…

Study led my Muntsa Roca-Martí published in Elem. Sci. Anth. examining the composition, modification, and export of particulate bioelements (C, N, P, Si) at Ocean Station Papa. This comprehensive characterization of marine particles was conducted as part of the first EXPORTS field campaign in the northeast Pacific, and the paper is part of a special…

Review of recent developments in the study of trace elements and their isotopes in the ocean published today. This study rounds out a Virtual Special Issue of Chemical Geology entitled: Cycles of trace elements and isotopes in the ocean – GEOTRACES and beyond…, and is authored by the Guest Editors: Tim Conway, Tristan Horner, Yves Plancherel, and…

Study led by Ann Dunlea and Logan Tegler published in Chemical Geology. This study investigates how pelagic clays can record the iron isotope composition of seawater and explores what these records reveal about iron cycling in the South Pacific over the last 95 million years. Full citation: Dunlea, A. G., Tegler, L. A., Peucker-Ehrenbrink, B.,…

Barium Isotopes, published today by Cambridge University Press as part of the series Geochemical Tracers in Earth System Science. Led by Tristan Horner and Peter Crockford, the book reviews the latest and greatest developments in barium isotope geochemistry. Full citation: Horner, T. J., & Crockford, P. W. (2021). Barium Isotopes: Drivers, Dependencies, and Distributions through…

Study led by Kim Mayfield published in Nat. Commun. illustrating the impact of groundwater inputs on marine isotope budgets (including for barium!). Full citation: Mayfield, K. K., Eisenhauer, A., Ramos, D. P. S., Higgins, J. A., Horner, T. J., Auro, M., Magna, T., Moosdorf, N., Charette, M. A., Gonneea, M. E., Brady, C. E., Komar,…

Study led by Dalton Hardisty published in Earth Planet. Sci. Lett. showing surprisingly slow rates of iodate reduction in the Eastern Tropical North Pacific, implying that water mass mixing is an important control on the relationship between dissolved oxygen and iodine speciation in oxygen-minimum zones. Full citation: Hardisty, D. S., Horner, T. J., Evans, N.,…

Study led by Francisca Martínez-Ruiz published in Front. Earth Sci. showing similar patterns of barite precipitation throughout the mesopelagic ocean, suggesting a common (organo)mineralization driving process. This paper is part of a special issue entitled: The Oceanic Particle Flux and its Cycling Within the Deep Water Column. Full citation: Martínez Ruíz, F. C., Paytan, A.,…