Geochemical fractionation of radiocesium in coral atoll soil

This study investigates the fractionation of 137Cs across the geological phases of coral soils using a sequential extraction scheme. For three of the four soil samples analyzed, the largest fraction of radiocesium (70–80%) was associated with the final fraction or “acid-soluble” phase of soil, which would typically include clays and other refractory minerals that are difficult to destroy. This is common behavior for radiocesium due to its strong affinity for clays, but surprising here because these primarily calcium carbonate soils contain very minimal amounts of such minerals.