LAUSR

Carbonate hosted intermetallic compound in the Umarvaniyan area is localized within the intensively sheared (mylonitised) dolomite in a NW–SE shear zone (~15 km), belongs to Salumber Ghatol metallogenic belt, in Debari Group of Aravalli Craton, Rajasthan, India. It is characterized by extensive silicification and ferruginisation with hematite, goethite, magnetite and native gold specks. The intermetallic compound within the dolomite is composed of varying proportion of Cu–Zn–Ni–Os–Fe which has been detected by electron probe microanalysis (EPMA) study. The EMPA (WDS) results of the intermetallic compounds also reveal occurrences of intermetallic compounds of Cu–Zn–Ni–Os–Fe and native Au. The occurrence of these non-separable compounds is probably because these metals were formed at very high temperatures and in reducing condition during the evolving shear with low oxygen and low sulfur fugacity. The fast cooling effect thereafter probably made the geochemical environment least conducive for reaction between Cu/Zn/Ni and sulphur or oxygen.