LREE enrichment in carbonatite from Khaderpet, Eastern Dharwar Craton, south India

An account of enriched light rare earth elements (LREEs), petrographic features, geochemical character, and stable isotope (C & O) concentrations in carbonatite occurring in association with kimberlite clan rock (KCR) at 3–016 prospect, Khaderpet, Anantapur dt., Andhra Pradesh within the Wajrakarur Kimberlite Field (WKF), Eastern Dharwar Craton is presented. The ‘Khaderpet carbonatite (KC) was discovered by Rio Tinto Exploration in 2002. The KC intrudes into kimberlite pipe, which is emplaced in granites of Archaean age. The pipe is expressed as a hard carapace of granite-kimberlite breccia which is one of its kind. In this investigation, total of 10 fresh outcrop samples of carbonatite have been analysed. Petrographically, the carbonatite is dominated by calcites showing massive equigranular texture. Occasional accessory minerals like chlorite, apatite are seen. REE bearing minerals like monazite, titanite and allanite are seen in the studied thin sections. The ∑REE ranges from 4100 to 4500 ppm of which ∑LREE contributes maximum, i.e., 4092 to 4509 ppm. The Sc ranges from 43 to 50 ppm. These results are analogous with the global carbonatite average REE. Geochemistry and Stable isotopes have confirmed that carbonatite is of magmatic origin. KC shows ‘mineralised’ nature in geochemical diagrams. Although the intrusion is smaller in magnitude, it warrants detailed quantification in terms of its anomalously enriched LREE content and presence of diamonds.