Search for Placer Gold in Leastern India - A Geomorphological Approach

In eastern India, presence of gold is common both in alluvial and colluvial zones in a sporadic fashion over wide stretches of Purulia district, West Bengal and adjacent Singhbhum and Ranchi districts, Bihar. Regionally, the area is in between the Tamar - Porapahar shear zone in the north and the Dalma range in the south.

Applied geomorphological studies, using remote sensing data products, with morphogenetic approach based on terrain analysis and classification help to outline such zones as manifestations of form - process - material interactions. With this perspective, interpretation of satellite imagery (B & W, TMFCC - LANDSAT) and aerial photographs has led to identification of relics of an 'Older planation surface' of Quaternary age in the Banduan area, Purulia district. West Bengal and Tamar - Ichagarh area, Ranchi and Singhbhum districts, Bihar.

The different terrain units/sub-units, with placer gold concentration, associated with this 'Ranchi - Purulia Older planation surface' are degraded glacis, very degraded glacis. cone glacis. The 'degraded glacis' with latosol/laterite crust (nodular ferricrete only) could be used as a guide horizon for preliminary search of placer 'gold in laterite' or 'lateritic gold' as has been reported from Brazil, Australia, West Africa and some Gulf countries in a similar set up.