3. Supergene enriched iron ores: Weathering, alteration and enrichment of Precambrian BIFs under surface conditions during Tertiary and Quaternary periods have produced abundant haematite rich supergene iron ores especially in Sandur and Chitradurga schist belts. These ores are friable, powdery and easily extractable form and contain 62 to 68 % Fe. These are the most preferred iron ores at present in domestic as well as export markets.
