The uranium provinces of the Lagoa Real District-Bahia (Brazil)

The Lagoa Real Project from NUCLEBRAS represents one of the most important uranium provinces in Brazil today. The project is limited by the 42000' - 42030'W and 13030' - 14015'S geographic coordinates, covering an area of 4,540 square kilometres in the South-Central part of Bahia State. Since 1977, 13 radiometric anomalies have been detected. As part of the Archean basement, metasomatized and cataclastic metamorphic rocks outcrop in the area. The uranium mineralization occurs in albitite bodies parallel to its foliation and is represented by fine grained uraninite. Lying roughly in N-S direction the albitite bodies are tabular and elongated. Each albitite body may reach over 1 Km of extensoin, 100m of width, and 350m of depth. 207Pb/206Pb age determination indicated 820 my as the age of uraninite crystallization. An ore reserve of 27,000 ton of U3O8 at an average grade of 0.15% U3O8 has been determined following geologic, topographic, and radiometric survey over an area of 700 hectares and the completion of 160 drill-holes totalizing 23,000 metres. The potential uranium reserve of the Lagoa Real District has not as yet been properly evaluated because from the known orebodies only six have been sistematically investigated to date. (Author)