Q. Rocks of which era are called 'reserves of metallic minerals' in Jharkhand?
Answer: Dharwad Era
Notes: Dharwad Era rocks are known for large deposits of metallic minerals like iron, copper, gold, and nickel in Jharkhand. These rocks formed through erosion and deposition of Archaean rocks. The Kolhan division of Jharkhand prominently contains Dharwad rocks, making them a significant metallic mineral reserve. Archaean rocks solidified from liquid earth, whereas Dharwad rocks originated later, facilitating mineral accumulation on a large scale.