Identifica？？o gamaespectrométrica de placeres rutilo-monazíticos neoproterozóicos no sul da Faixa Seridó, nordeste do Brasil

aerial gamma-ray survey data covering neoproterozoic supracrustal sequences in the seridó belt were processed and analyzed together with ground gamma-ray data, air photos and geological data for lithogeophysical characterization and mapping of granitic rocks, related pegmatites fields and lithological units of seridó group. interpretation was based on individual and ternary images of the three radio-elements and the eu/eth and eth/k ratios, and allowed the discovery of thorium anomalies associated with coarse-grained metarenites and metaconglomerates facies intercalated with quartzites of the equador formation. high contents of iron oxides, ilmenite, monazite, rutile, titanite and zircon were identified by ore microscopy of polished sections in the metaconglomerate's matrix. semiquantitative scanning electron microscopy (sem) analyses in minerals of two samples revealed up to 79.4% of th02 and 87.7% of ree in monazites; up to 99.2% of ti02 in ilmenite and rutile and up to 1.81 % of hfo2 in zircon. gamma-ray anomalies due to thorium were also identified in association with sediments of cenozoic age in the region.