LAUSR

Presence of uranium mineralisation associated with migmatites is reported from Chhotanagpur granite gneiss complex (CGGC) along Baran and Gabala river section in parts of Singrauli district of Madhya Pradesh. Nine radioactive bands along the Baran river and three radioactive bands along Gabala river section near Jhanji hosted by migmatites leucosomes with variable dimensions have been located. The trend of migmatite is E-W to WNW-ESE and dips of 50°–60° N. Grab samples of radioactive migmatite leucosomes from Baran river assay from 93.28 ppm to 534 ppm U and 21.97 ppm to 254 ppm Th, whereas Gabala river migmatites analysed 127.19 ppm to 8564.4 ppm U and 21.97 ppm to 105.48 ppm thorium. Uraninite is the main uranium mineral identified in the leucosome from both the localities. Chemical age of single uraninite grain from Gabala river migmatite is 792Ma age which suggest that uranium mineralisation/uraninite crystallisation in migmatite took place during Neoproterozoic. Euhedral shape of uraninite grain, their high U/Th ratio, high REE content and high unit cell dimension(a0) suggest that uranium mineralisation in migmatite took place at moderate to high temperature hydrothermal fluid. In view of uraniferous nature and their dimension, migmatites of the area warrant detailed exploration to establish migmatite hosted U-mineralisation.