Specific activity of radioisotopes of different types of iggmatic rocks of the Amuro-Zeiya depression

The average values of the specific activity of beta-emitting isotopes 40K, 137Cs and gamma-emitting isotopes 40K, 137Cs, 222Rn, 224Ra, 226Ra, 228Ra, 232Th and 228Th in igneous rocks of the Amur-Zeya depression were established. During the research, granites, granodiorites and diorites of the Ordovician October magmatic complex and andesites of the Cretaceous Poyarkovsky igneous complex were examined. The specific activity values of beta- and gamma-emitting light isotopes 40K and 137Cs decrease from acidic rocks (granites, granodiorites) to more basic varieties (diorites, andesites). A similar picture is observed for the gamma-emitting heavy isotopes 40K, 137Cs, 222Rn, 224Ra, 226Ra, 228Ra, 232Th, 228Th. A positive correlation of igneous rocks of average composition of the Oktyabrsky and Poyarkovsky complexes with gold has not been established.