A prospective gold mine found near Bengaluru

Our exploration so far is encouraging enough to move on to the next stage and take a step towards mining the precious metal

M SRIDHAR, additional director and head, southern region, GSI

move onto the next stage...,” said M Sridhar, additional director and head, southern region, GSI,

For a gold-obsessed country like India, the amount of the quantity of the precious metal actually mined in the country is incredibly little. Out of an annual consumption of about 900 tonnes, India produces merely 1-1.5 tonnes of gold and imports the rest. The Ajjanahalli gold prospect is part of the Chitradurga greenstone belt, a linear, north-to-south sequence of volcanic and sedimentary rocks of the Archean age around Chitradurga town.

“Some of the world’s most important gold resources occur within such Archean greenstone belts,” said M Santosh, a geologist and professor at the University of Adelaide in Australia. “In Karnataka, the Archean greenstone are potential hosts of gold mineralisation and have been historically explored and mined for gold, such as in the case of Kolar and Hutti. The new find of gold mineralisation in Karnataka by GSI further underlines the importance of the various Archean greenstone belts as hosts for the precious metal, and offers scope for further exploration...”

The first discovery of gold in the region was documented in 1849, but GSI started systematic geological mapping of Ajjanahalli only in 1980s. This was discontinued in 1991 before GSI started its second phase of exploration in the area in 2004. “We had several old or ancient workings to go by to decide on sites to explore,” a senior scientist at GSI, associated with the Ajjanahalli gold prospect said, requesting anonymity. Ancient workings are historical records of gold being mined in any given area.

The scientist added, “We have completed reconnaissance and preliminary exploration and are moving forward with general exploration. If we get positive results, we will recommend mining the area for gold ore.”

GSI has explored nearly 10 square kilometres in Ajjanahalli so far. As the GSI scientist cited above said, “There are probably more than 10 explorations happening across Karnataka for gold and among them, we believe Ajjanahalli shows great promise.”