Abstract:
Rare-earth phosphate minerals have been reported in the Banded Hematite Jasper (BHJ) of the Daitari Iron Ore Province, Singhbhum Craton, eastern India, through electron-microscope study, supported by electron microprobe analysis. The Rare Earth Element (REE) minerals identified are monazite and xenotime, occurring as discrete, micron-size (7-30 mu m) anhedral grains within hematite-jasper bands. The monazite grains are enriched in Light Rare Earth Elements (LREEs), with Ce2O3 (29-32 wt%), La2O3 (27-31 wt%), and Nd2O3 (similar to 1 wt%), whereas xenotime is dominated by Heavy Rare Earth Elements (HREEs), notably Y2O3 (45-49 wt%), Er2O3 (4-10 wt%), and Dy2O3 (2-3 wt%). Both phases contain abundant P2O5 (20-38 wt%) and traces of Th and U. The micro-structural and compositional results of the phosphate minerals indicate that the phosphate-rich fluid was possibly derived from some adjacent source, which was later subjected to diagenesis and low-grade metamorphism. These phosphate minerals sequester a significant proportion of the REE in the BHJ of the present set-up. The Daitari BHJ thus represents a potential micro-reservoir of REE-bearing phosphates within the Archaean Banded Iron Formation (BIF) regime of the Singhbhum Craton.
