Rare earth element association with foraminifera

• Published in: Geochimica et Cosmochimica Acta
• Main Authors: Roberts, Natalie L., Piotrowski, Alexander M., Elderfield, Henry, Lomas, Michael W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems; Planktonic foraminifera
• Online Access: http://eprints.esc.cam.ac.uk/2585/; http://eprints.esc.cam.ac.uk/2585/1/N_Roberts_s2.0-S0016703712004000-main.pdf; http://eprints.esc.cam.ac.uk/2585/2/Rare_earth_1-s2.0-S0016703712004000-gr1.jpg; http://www.sciencedirect.com/science/article/pii/S0016703712004000; https://doi.org/10.1016/j.gca.2012.07.009

Neodymium isotopes are becoming widely used as a palaeoceanographic tool for reconstructing the source and flow direction of water masses. A new method using planktonic foraminifera which have not been chemically cleaned has proven to be a promising means of avoiding contamination of the deep ocean palaeoceanographic signal by detrital material. However, the exact mechanism by which the Nd isotope signal from bottom waters becomes associated with planktonic foraminifera, the spatial distribution of rare earth element (REE) concentrations within the shell, and the possible mobility of REE ions during changing redox conditions, have not been fully investigated. Here we present REE concentration and Nd isotope data from mixed species of planktonic foraminifera taken from plankton tows, sediment traps and a sediment core from the NW Atlantic. We used multiple geochemical techniques to evaluate how, where and when REEs become associated with planktonic foraminifera as they settle through the water column, reside at the surface and are buried in the sediment.