Mineral exploration stages
Also called: G1 to G4 stages, UNFC · Topic: Mineral Resources of India: Distribution and Conservation · NCERT: Beyond NCERT
Meaning
Mineral exploration stages are the steps used to find out how much ore a deposit holds and how good it is. India uses the UN Framework Classification (UNFC). It goes from reconnaissance (G4), a first broad survey, to preliminary exploration (G3), then general exploration (G2), and finally detailed exploration (G1). Each stage gives more confidence about the deposit's size and grade. G1 gives the most confidence. In India, GSI does the exploring and the National Mineral Exploration Trust (2015) helps pay for it.
Example
In February 2023, GSI reported 5.9 million tonnes of inferred lithium resources at Salal-Haimana in Reasi district, Jammu and Kashmir, at the G3 stage. Because the grade was still uncertain, early auctions found no successful bidder (verify current).
Don't confuse with
- Inferred resource and proven reserve: a G3 "inferred" figure is only an estimate. It is not a proven, ready-to-mine reserve.