Geology of rare earths, niobium and uranium deposit from zero zone, Araxa, Minas Gerais State

The deposit has been formed by residual enrichment of a rare earth-rich carbonatite, which is now decomposed to more than 140 m of depth. The principal zone of enrichment reaches 20 m of thickness and is situated between the surface and the water level. Many samples assay more than 25% (TR)203, 4% Nb205 and 0,1% U308. Average grades for the 800.000 metric ton of proved reserves are 13,5% (TR)203, 2% Nb205 and 0,05% U308. Part of the mineralized area is covered by alluvium, responsible for the relatively low radiometric values at the surface. In profile, the mineralization is zoned, with a richer rare earth and uranium (monazite) strip intercalated with two other richer in aluminium and barium (goyazite). (author)