Análise prospectiva dos elementos radioactivos (U, Th, K) em sedimentos de corrente no distrito de Bárue, província de Manica

Abstract

Research in the Bárue district region is of great relevance due to the mineral potential that can be found in the area. Geological, geochemical and remote sensing analyzes provided valuable knowledge about the distribution and nature of Uranium (U), Thorium (Th) and Potassium (K) anomalies, indicating areas of interest for future mining exploration. The research focused on analyzing geochemical data from stream sediments using a portable gamma spectrometer. In this work, 62 samples were processed, providing more detailed data in relation to those that existed. Therefore, this contribution can now provide more details for more in-depth and valuable studies for mineral prospecting. Data integration was carried out, using geostatistical methods and GIS techniques, which allowed a more complete understanding of the distribution of anomalies and possible geological and structural controls in the study area. It is important to highlight that U, Th and K anomalies are associated with different rocks and soils in the region, which suggests the presence of different chemical-geological processes that influence their occurrence and mobility. Furthermore, the identification of structure as a control of anomalies highlights the importance of tectonics in the formation and distribution of these mineral deposits. The detected anomalies were superimposed on the GTK 2006 geological map and it was found that Th anomalies predominate in granite-gneiss (P3ROgm), saccharoid quartzite, quartzite schist (P1Zqs). Those of U are associated with muscovitic-biotitic schist (P1Zss), gneiss, granodiorite with amphibolic bands (A3Mqd) and biotitic muscovitic schist (P1Zss). Those of K are in TTG gneiss (A3Mgn), in contact with saccharoid quartzite, quartzite schist (P1Zqs) which suggests that the anomalies were controlled by lithologies. On the other hand, it was found that topography played a relevant role in them, illustrating that Th anomalies occur predominantly in low areas, K and U in slope areas. The “prospectivity” map made it possible to identify areas with greater potential for occurrences of U, Th and K, a tool that could be useful for mining companies and government institutions in planning mining exploration activities in a more efficient and targeted way, and could help in optimizing resources and minimizing risks associated with mineral exploration