Geochemical Indicators for Concealed Cu-Zn-Pb Mineralization in Rajpura, Udaipur, Rajasthan

Geochemical analysis of 73 rock samples collected from Rajpura 'B' and 'C' blocks has been carried out for 6 major (Fe, Mn, Mg, Ca, Na and K) and 8 minor (Cu, Zn, Pb, Ni, Ag, Cr, Co and Ti) elements. The results indicate anomalous geochemical patterns. Majority of the samples collected from gossan unit show more than 1000 ppm concentration for Pb, Zn and 500 ppm Cu. In calc-silicate-bearing-dolomite (CSD) and recrystallized-siliceous-dolomite (RSD), Pb-Zn-Cu values seldom reach 1000 ppm but they are of importance due to high mutual correlation. The correlation between different trace elements indicates that there exists a positive correlation between elements Cu-Zn-Pb-Ni-Co and antipathetic relationship between these elements and Ag and Cr. The elemental dispersal is controlled by their relative mobilities in an environment which is secondary, acidic and oxidizing.

The study shows that CSD and RSD are suitable lithounits for mineralization with former being favourable for Cu-Zn and latter for Pb and Zn. Mineralization in graphite-mica-schist (GMS) unit is likely to be confined to weak fracture zones.