Papers

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.,…

Study led by Sune Nielsen published in Geochim. et Cosmochim. Acta exploring the ‘ins and outs’ of the Aleutian and Ryukyu Arcs, showing only minor fractionations associated with Ba mobilization from the down-going slab, thus underscoring the utility of Ba isotopes to apportion fluid sources to arc magmas. Full citation: Nielsen, S. G., Shu, Y.,…

Study led by Haifeng Fan published in Geobiol. showing a significant perturbation to marine redox conditions during the Shuram negative C isotope excursion. Full citation: Fan, H., Nielsen, S. G., Owens, J. D., Auro, M., Shu, Y., Hardisty, D. S., Horner, T. J., Bowman, C. N., Young, S. A., & Wen, H. (2020). Constraining oceanic…

Study led by Dalton Hardisty published in Chem. Geol. reporting direct evidence of iodide oxidation under marine-analogue conditions, made possible by the development of a novel, high-sensitivity MC-ICP-MS method. Full citation: Hardisty, D. S., Horner, T. J., Wankel, S. D., Blusztajn, J., & Nielsen, S. G. (2020). Experimental observations of marine iodide oxidation using a…

Study co-led by Ben Geyman and Jamie Ptacek published in Earth Planet. Sci. Lett. assessing the utility of deep-sea bamboo corals from the northeast Pacific to record ambient barium-isotopic chemistry. Full citation: Geyman, B. M., Ptacek, J. L., LaVigne, M., & Horner, T. J. (2019). Barium in deep-sea bamboo corals: Phase associations, barium stable isotopes,…

Study led by Malcolm Hodgskiss published in Proc. Natl. Acad. Sci. examining the rapid reduction in biosphere size following Great Oxidation Event. Full citation: Hodgskiss, M. S., Crockford, P. W., Peng, Y., Wing, B. A., & Horner, T. J. (2019). A productivity collapse to end Earth’s Great Oxidation. Proceedings of the National Academy of Sciences,…