According to a new study published in the journal PNAS, the continents rose from the oceans about about 3.2 billion years ago and that the earliest continental landmass to emerge may have been Jharkhand’s Singhbhum region.
- The widely accepted view is that the continents rose from the oceans about 2.5 billion years ago, but the new study has challenged this and suggests this happened 700 million years earlier.
- Scientists have found sandstones in Singhbhum with geological signatures of ancient river channels, tidal plains and beaches over 3.2 billion years old, representing the earliest crust exposed to air.
- The researchers studied the granites that form the continental crust of Singhbhum region.
- The researchers say, these granites are 3.5 to 3.1 billion years old and formed through extensive volcanism that happened about 35-45 km deep inside the Earth and continued on-and-off for hundreds of millions of years until all the magma solidified to form a thick continental crust in the area.
- Patches of the earliest continental land, however, exist in Australia and South Africa, too.
(Source: IE)
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