One of the ways to reconstruct past ocean temperatures, is by measuring Mg/Ca in foraminiferal tests. To obtain a truly temperature signal, we must follow a carefully designed protocol to clean the fossil tests and remove contaminants that bias the final results. Silicate grains, manganesse coating, and organic matter are some of the things that contain Mg and end up in the fossilized forams. The presence of such contaminants is measured at the same time as Mg/Ca: Al/Ca, Fe/Ca, and Mn/Ca ratios.

In this project, we want to quantify the effects of cleaning protocols on the measured chemical composition of foraminiferal tests, by measuring the ratios at different stages of the cleaning protocol. The study is being carried out by the Paleocenography Working Group at the Institute of Geosciences of Kiel University and aims to provide guidelines and threshold values of acceptable versus critical contamination indicators to the Paleoceanography community.