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K. Bangaku Naidu ¹, K. S. N. Reddy ¹, Ch. Ravi Sekhar ¹, P. Ganapati Rao ¹, K. N. Murali Krishna ¹

Affiliations
1 Department of Geology, Andhra University, Visakhapatnam 530 003, IN

Abstract

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.

Keywords

Coastal Sand Deposits, Geochemical Dating, Khondalites, Monazites, Rare Earth Elements.

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