Ree Geochemistry of Monazites from Coastal Sands between Bhimunipatnam and Konada, Andhra Pradesh, East Coast of India

The rare earth elements (REE) geochemistry of monazites of Bhimunipatnam-Konada coastal sand deposit was studied using EPMA method. The average LREE concentration was 53.31%, which is more than HREE (av 1.38%)ΣLREE more than actinides (Th + U) indicates that provenance for monazite in the study area is garnet-bearing paragenesis rocks such as charnockites and metapelitic rock (khondalite). The REE fractionation patterns and positive europium anomalies indicate that monazites were formed from magma/ anatectic melt with high oxygen fugacity. The U-Th- Pb geochemical dating of monazites is 1000 Ma (average), which indicates that they are derived from protoliths of charnockites and metapelitic rocks such as khondalites, which are formed during meso-neo- Proterozoic ages in the Eastern Ghats Granulite Belt.