Comparative repartition of 226Ra, 238U, 234U, 230Th and 232Th in a variety of soils sampled from geological formations in the NE of the Basin of Paris

Abstract

• U, 234 U, 230 Th and 226 Ra were determined in soils sampled on geological formations from the NE of the Basin of Paris. • Ra is correlated with the finest soil fraction (<2 µm), suggesting this latter is involved in the retention of radium. • The enrichment of soils in 226 Ra compared to 238 U and 230 Th is associated with mica-like mineral, i.e. illite-smectite. • Unlike soils, litters exhibit 226 Ra depletion compared to both 238 U and 230 Th which remains poorly explained up to now. • The retention of radium in the soil and/or degradation process of the litter are assumed to explain litters signatures.