La spettrometria gamma per lo studio dei radionuclidi naturali delle rocce : il plutone della Valle del Cervo

Monitoring of the γ radiation in Valle del Cervo Pluton was performed by determining uranium and thorium contents in the main rock types cropping out over the entire area and pertaining to the Granitic Complex, Syenitic Complex and Monzonitic Complex. All the samples are fresh and do not present joints or fractures filled with uranium minerals. In the crushed samples the activity of uranium varies from 345 to 763 Bq/kg. Concentration of thorium varies from 202 to 478 Bq/kg. For all the analysed rocks uranium activity is higher than thorium one. The lowest value of radioactive concentration is referred to rocks of the Granitic Complex. The most active rocks are syenites. The data confirm the high activities of Valle del Cervo rock types, strongly connected with high potassium content of the source magma (geochemical signature); on the contrary, the activity seems to be not related to the location of the samples.