Uranium and REE potential of the albitite-pyroxenite-microclinite belt of Rajasthan, India

A number of radioactive albitite, pyroxenite and microclinite occurrences have been identified in north and central Rajasthan, along or in close proximity to major lineaments, from Dancholi - Mewara in the NE to Tal in the SW. With these new findings the total extent of Albitite belt of Rajasthan now stands at over 320 km. These occurrences have been evaluated on the basis of their U, Th and REE content to identify the potential areas for the second phase of uranium exploration programme. Further, based on the various characteristic features of radioactive host rocks, the Albitite Belt has been divided into five sectors. The U3O8 content of albitites varies from 0.008 to 0.44% and of pyroxenites from 0.022 to 2.0% whereas ThO2 varies from < 0.005 to 0.83% in albitites and <0.005 to 0.033% in pyroxenities. These albitites, microclinites and pyroxenites are also characterised by anomalous concentration of REEs. Uranium and REE bearing phases are represented by uraninite, brannerite, davidite, fergusonite, monazite, anatase, rutile, zircon, allanite and britholite. The data accrued so far suggest that U and REE potential of the Mewara-Maonda and Hurra Ki Dhani-Rohil sectors are very high and hence needs further detailed integrated exploration. (author)