Enrichment characteristics of radioelements in various types of rock from Sambalpur district, Orissa, India

摘要

Over the years a large number of rock samples were collected by the explorationists of Atomic Minerals Directorate for Exploration and Research (AMD), Department of Atomic Energy from Sambalpur district, Orissa, India. The variation of uranium enrichment with various types of rock in these samples was studied with an aim to help quick reviewing of toposheets in case of newly taken up areas, for uranium exploration. The radioelements U, Th and K determined for these samples are plotted in ternary diagrams for classifying them as being uraniferous or thoriferous with respect to various type of rocks, keeping the total natural content of radioelements (expressed by eU_3O_8) as a parameter. In this study it is seen that samples of quartzofeldspathic breccia type are enriched in uranium irrespective of their further sub classification and eU_3O_8 content. Granites are enriched in thorium when eU_3O_8 < 100 ppm and are enriched in uranium when eU_3O_8 > 100 ppm. A database prepared for this purpose may be useful for reviewing toposheets in future.