Activities of the ²³⁸ U, ²³² Th decay chains and for ⁴⁰K and calculated beta dose rates.

For the Uranium family, the activities deduced from the 234Th (pre 226Ra–“top”), from the 214Bi and 214Pb contents (post 226Ra_ “middle”), and from 210Pb (“bottom”) are displayed. a) fraction< 2 mm, b) fraction > 2 mm and < 1 cm, c) mean activity and dose rate calculated from a) and b), taking into account the relative weight of each fraction.