Petrography and geochemistry of the radioactive albitites and their genesis: Maonda Area, north Rajasthan

A partly concealed radioactive alibitized pegmatoid/quartz albitite body (1 200 m x 0.5 to 20 m) containing 0.010 to 0.190% U3O8 and 0.007 to 0.076% Th O2 and about 20 brick red coloured albitite lenses varying in dimension fro m 13 m x 7 m to 220 m x 12-30 m and containing 0.022 to 3.50% U3O8 and <0.0 05 to 0.034% ThO2 are described at Banjaron Ki Dhani, near Maonda in north Rajasthan. Davidite, brannerite, rutile, anatase, zircon, monazite and trac es of uraninite have been identified in the albitites. A metasomatic origin for the albitites is suggested. The distribution of albitites along NE-SW to NW-SE and E-W trending weak structural planes and the coincidence of 'Al bitite Line' with Kaliguman lineament, demonstrates the tectonic control of albitization.