Hydrogeochemistry as a Tool for Platinum Group Element (PGE) Exploration - A Case Study from Sittampundi Anorthosite Complex, Southern India

The use of surface and ground water for exploration of platinum group elements (PGE) has been studied in the Sittampundi anorthosite complex, Tamil Nadu, south India, where PGE mineralization is known to occur in basic and ultrabasic rocks. Groundwater interacting with mineralized rocks creates a geochemical signature which can be linked to the occurrence and distribution of PGE, especially Pd because of its leachability and relatively high mobility in aqueous environment. Forty surface and ground water samples collected from the area were analyzed for PGE and several other major, minor and trace elements using high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) to investigate the distribution patterns of individual PGE and other elements for the purpose of evaluating the utility of hydrogeochemistry as a tool for PGE exploration studies. Ground and surface water chemistry reflected the chemical composition of host lithology, particularly the basic-ultrabasic rocks of the region, with the dispersion of PGE and high anomalous concentrations of Pd, Ru and Rh along with several other metals such as Zn, V, Cr and Ni indicating PGE mineralization. The results of this study suggest that groundwater chemistry has significant potential as a PGE exploration tool with advantages such as rapid and lowcost sampling, high contrast anomalies and a uniform sampling medium.