High resolution I/Ca ratios of benthic foraminifera from the Peruvian oxygen-minimum-zone: A SIMS derived assessment of a potential redox proxy

Measurements on cross-sections of uncleaned U. striata specimens revealed a strong contaminant iodine phase within the massive centre of the foraminiferal test walls which usually would be considered to be free of contamination. The contaminant iodine is probably associated to organic matter and located inside a microporous framework within the foraminiferal calcite. This might be related to microtubular structures which have been revealed in previous studies during early dissolution states of foraminiferal test walls.