The Dharwar System

Some of India’s oldest rocks hold no fossils at all. They also hold most of the country’s gold.

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Indian Geography · IndGeo0071

The Dharwar System

India’s oldest rocks — no fossils, but plenty of gold

2.5+ billion yrs

Formed in the Archean era

Dharwad, Karnataka

Where first studied, and namesake

Key minerals hosted by the Dharwar System

Gold Iron ore Manganese Copper Chromite

Zero fossils, deep gold

Billions of years of intense metamorphism destroyed any trace of ancient life in these rocks. Yet the same rocks host the Kolar Gold Fields, whose Champion Reef is one of the deepest gold mines in the world.

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Must Know

• The Dharwar System is India’s oldest metamorphosed sedimentary rock system.
• It formed during the Archean era, more than 2.5 billion years ago.
• It is named after Dharwad, the town in Karnataka where these rocks were first studied.
• The main belt runs through Karnataka’s Dharwad and Shimoga districts.

Good to Know

• The system includes schists, quartzites, phyllites, slates, and crystalline limestones and dolomites.
• These rocks contain no fossils.
• Intense metamorphism over billions of years destroyed any trace of ancient life forms.
• Beyond Karnataka, related Dharwar-age rocks also appear in Jharkhand, Chhattisgarh, Odisha, and parts of the Himalayas.

Test Yourself

Please wait…

1. The Dharwar System is named after a town in which state, where these rocks were first studied?

Karnataka

Andhra Pradesh

Tamil Nadu

Maharashtra

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Great to Know

• The Dharwar System is one of India’s most economically important rock systems.
• It holds rich deposits of gold, iron ore, manganese, copper, and chromite.
• The famous Kolar Gold Fields sit within this same rock system.
• Kolar’s Champion Reef mine is one of the deepest gold mines in the world.
• So the same ancient, lifeless rocks that record none of Earth’s early biology have shaped one of India’s most productive mining regions.