Natural radioactivity in rocks of the Modane-Aussois region (SE France)

Abstract

The activity concentrations of 40 K, 232 Th, and 238 U in the characteristic rocks of the Modane-Aussois region (Western Alps, France) were determined using an HPGe gamma-ray spectrometry system. The activity concentrations of 40 K varied from 18 Bqkg -1 (limestone dolomite) to 392 Bqkg -1 (calcschist), while those of 232 Th varied from 0.7 Bqkg -1 (limestone dolomite) to 18 Bqkg -1 (calcschist). The activities associated with 238 U ranged from 9 (quartzite) to 29 Bqkg -1 (dolomite). In the investigated rock samples, concentrations of 238 U (ppm) and 40 K (%) had a strong negative correlation. © 2011 The Author(s).