U, Th Enrichment in Cesium Bearing Aplitic Pegmatite of Belamu (North) Area, Purulia District, West Bengal with Special Reference to Monazite Group of Minerals

Cesium bearing aplitic pegmatites of Chhotanagpur Gneissic Complex Purulia district West Bengal show enrichment in U and Th through at least one phase of lanthanide actinide rich hydrothermal activity Monazite group of minerals with Th and REE are hosted by the aplitic pegmatites with varying texture and composition Monazite (Ce) occurs as inclusions within quartz and feldspar with evolutionary tiend from huttonitic monazite at core to monazite (Ce) at rim Се/Sm ratio varies from 811 to 25 67 representing a wider evolutionary trend of the melt from which monazite crystallized Principal component analysis shows different substitution phenomenon in mona/itc Chemical variations indicate the huttonitic monazite to be a primitive component which was transformed to monazite (Ce) by interaction with LREE P-rich fluid