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

•U, 234U, 230Th and 226Ra 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 226Ra compared to 238U and 230Th is associated with mica-like mineral, i.e. illite-smectite.•Unlike soils, litters exhibit 226Ra depletion compared to both 238U and 230Th 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.