According to a recent study, there is a probability that earth’s first continents might have arisen from the ocean around 700 million years earlier than thought. Surprisingly, Jharkhand’s Singhbhum region may have been the earliest continental land to emerge from the ocean around 3.2 billion years ago, a study has indicated.
A previously acknowledged fact that continents emerged from the ocean approximately 2.5 billion years ago has been challenged, as some scientists from India, Australia and US have found otherwise. Sandstones in Singhbhum have been found with some geological signatures of ancient river channels, tidal plains and beaches over 3.2 billion years old, establishing the earliest crust visible to air.
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Dr. Priyadarshi Chowdhury of Monash University, the study’s lead author explained that he and his team found sandstones and explored their age by analyzing the uranium and lead contents of tiny minerals. The results showed that those rocks were 3.1 billion years old and were formed in ancient rivers, beaches and shallow seas.
The water bodies would not have been there if there was not any continental land, therefore the team culminated that the Singhbhum region was above the ocean over 3.1 billion years ago. Some areas of continental land also exist in Australia and South Africa.
We studied the granites that form the continental crust of the Singhbhum region. 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,
Chowdhury explained.
Because of the thickness and less destiny, the continental crust arose above the oceanic crust. The verdicts of the findings have appeared in the Proceedings of the National Academy of Sciences, a US research journal.
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As per the research, the first continents possibly arose above sea level because of the progressive inoculation of magma that originated from deep within the earth. The initial emergence of continents would have backed the proliferation of photosynthetic organisms, which would have improved oxygen levels in the atmosphere.
As far as climate change is concerned, it is very important to know the geological processes involved in the formation of the atmosphere, oceans, and climate to get a better idea about our planet.
Image: Indian Express
Via: The Indian Express