Singhbhum Craton

Why in News?

Researchers recently identified a 3.5-billion-year-old layered rock formation within the Singhbhum Craton in eastern India. The formation could contain some of the earliest chemical evidence of life on Earth.

About Singhbhum Craton

The Singhbhum Craton is located in eastern India, mainly across Jharkhand and Odisha. It lies between the Chhota Nagpur Plateau and the Eastern Ghats.

It is one of the oldest and most important cratons of the Indian Shield and has significant geological and economic importance because of its rich mineral resources.

What is a Craton?

A craton is a stable continental block composed mainly of ancient crystalline rocks and is generally surrounded by mobile belts.

Cratons provide an important window into the ancient geological history of Earth, as their rocks preserve evidence of processes that operated within and on the surface of the planet billions of years ago.

Geological Age and Origin

Previous research has shown that parts of the Singhbhum Craton date back to around 3.5 billion years.

The craton represents a fragment of the ancient Gondwana supercontinent and preserves some of the oldest geological records of the Indian subcontinent.

Greenstone Successions

The oldest rock assemblages of the Singhbhum Craton are largely composed of volcanic and sedimentary rocks, commonly referred to as greenstone successions.

Greenstones are rock assemblages consisting predominantly of submarine volcanic rocks, along with smaller amounts of sedimentary rocks.

These geological formations are particularly important for understanding the Archaean Earth and the environmental conditions that existed during the early stages of the planet's history.

Similarity with Other Ancient Geological Regions

The geology of the Singhbhum region shows strong similarities with ancient greenstone belts found in South Africa's Barberton and Nondweni areas and the Pilbara Craton of Western Australia.

These regions experienced widespread submarine mafic volcanic eruptions between approximately 3.5 and 3.3 billion years ago.

The term mafic refers to rocks that are relatively rich in magnesium and iron, with the source specifically highlighting their high magnesium oxide content.

Evidence of these ancient volcanic activities has been preserved in the form of pillowed lava and komatiites.

Significance of Singhbhum Craton

The Singhbhum Craton provides important evidence for understanding Earth's early geological and tectonic processes during the Archaean Eon.

Its greenstone belts and other ancient geological formations provide valuable information about the evolution of Earth's surface and atmospheric conditions.

These geological records are also important for developing hypotheses about early habitable conditions and the possible emergence of life on Earth.

The newly identified 3.5-billion-year-old layered rock formation is particularly significant because it may preserve some of the earliest chemical signatures associated with life.