A NOTE ON THE KALADUNGAR PHOSPHORITE OCCURRENCE, JAISALMER DISTRICT, RAJASTHAN

Kaladungar phoshorite occurrence represents the Jaisalmer-Baisakhi transition zone of Middle to Upper Jurassic age. Phosphatic nodules are sporadically distributed in marls and marly calcarenite of Jaisalmer Formation and exposed over a potential area of 0.4 sq km with an average thickness of 0.35 m, while Baisakhi shales contain rive phosphatic nodules bearing bands varying in thickness from 0.10 m to 0.35 m. They cover an area of about 0.60 sq km. Preliminary estimate shows that the prospect may have total geological reserves of 2.68 million tonnes with average grade of 12.75% P2O5. The nodules show solubility in 2% formic acid between 34.5% and 39.9% and neutral ammonium citrate between 9.76% and 16.31%.