News Excerpt:

Singhbhum Craton’s unique geological features, including its greenstone belts, provide invaluable information about Earth’s surface and atmospheric processes. 

• This is crucial for hypothesising early habitable conditions and the emergence of life on Earth.

Key highlights of the study:

• While scientists know what types of rocks originated roughly 3.5 billion years ago, they still don't fully comprehend the geological processes that generated these formations.
• Evidence is preserved in ancient volcanic and sedimentary rocks dating back to the Archaean age, between 4 billion and 2.5 billion years ago.
• These rocks are found in the oldest parts of the present continents, called cratons. 
• Cratons are pieces of ancient continents formed billions of years ago. 
• Studying them explains how processes within and on the surface of Earth operated in the past. 
• One example is the Singhbhum Craton, in the Daitari Greenstone Belt in the state of Odisha in eastern India. 
• The craton’s oldest rock assemblages are largely volcanic and sedimentary rocks, also known as greenstone successions. 
• Greenstones are rock assemblages made up mostly of submarine volcanic rocks with minor sedimentary rocks.

Key findings from the study of rocks from the Singhbhum Craton:

• The geology of Singhbhum Craton shares stark similarities with the greenstone belts documented in South Africa’s Barberton and Nondweni areas and the Pilbara Craton in Western Australia.
• All these areas experienced widespread submarine mafic – meaning high in magnesium oxide – volcanic eruptions between 3.5 and 3.3 billion years ago, preserved as pillowed lava and komatiites.
• This differs from silicic (elevated concentration of silicon dioxide) volcanism, which research has shown was prevalent around 3.5 billion years ago.

About Singhbhum Craton (SC):

• Singhbhum Craton lies between Satpura Mobile Belt in the east, north and north-west and Eastern Ghat Mobile Belt in the south. 
• It is separated from Bastar Craton by Mahanadi Graben. 
• It is located in the northern parts of Odisha and Jharkhand. 
• The Singhbhum region of southern Bihar and its contiguous regions of Mayurbhanj, Keonjhar and Bonai of Sundergargh districts of Odisha are well known for their rich deposits of iron and copper. 
• The Singhbhum Shear Zone traverses the region. 
• It separates a northern terrain of more highly metamorphosed rocks and a southern terrain of relatively less metamorphosed rocks.
• It provides a well-preserved and extensive Archean geological record.
• The SC of Eastern India comprises large economic grade reserves of Fe, Mn, Cr, PGE (platinum group elements), Ti, Au, U, Cu, P, REE (rare earth elements) and W (Tungsten) ores along the peripheral part of the central granitic pluton.