Abstract:
The geochemistry of radioactive elements in coals of northern Asia have been studied. By quantitative methods as the instrumental neutron_activation analysis, method of delayed neutrons and X_ray_fluorescent analysis more than 6000 coal and peat samples have been investigated. The average content of uranium in the coals of deposits and basins of the region is ranging from 0.4 to 32.8 ppm and for thorium - from 0.8 to 32.0 ppm. Within the bounds of basins, deposits and separate coal layers a lateral changing and a vertical one in the distribution of radioactive elements have been studied. The high concentrations of U and Th in coal deposits relate spatially to rock blocks within basin frames, which are enriched with elements, or are connected with a volcanism of a period of coal formation. A consistent changing of a role of pyroclastic material at the radioactive elements accumulation was determined in the direction from the West to the East.