Sign In
Learn bits
Geography
Mahesh

12/08/22 01:00 AM IST

Giant meteorite impacts could be responsible for Continents formation

In News 
  • Earth’s continents were formed by massive meteorite impacts that were prevalent during the first billion years of our planet’s four and a half billion-year history, according to a new study.
About the study 
  •  The researchers looked for evidence in zircon crystals embedded in rocks from the Pilbara Craton in Western Australia. This craton is the remnant of an ancient crust that began forming more than three billion years ago.
  • A craton is an old and stable part of the continental lithosphere, which consists of Earth’s two topmost layers, the crust and the uppermost mantle.
  • Studying the composition of oxygen isotopes in these zircon crystals revealed a ‘top-down’ process starting with the melting of rocks near the surface and progressing deeper, consistent with the geological effect of giant meteorite impacts.
  • Zircons are formed by the crystallisation of magma or are found in metamorphic rocks. They act as tiny time capsules, recording the period of geologic activity. Newer zircon adds to the original crystal as time progresses.
Significance 
  • Understanding the formation and evolution of continents is important, as it is the key to reserves of metals such as lithium, tin and nickel.
  • Most of Earth’s biomass and most humans live on these landmasses, so understanding how continents form and evolve is crucial.
Theory of plate Tectonics 
  • Alfred Wegener in his paper in 1912 hypothesized that all of the modern-day continents had previously been clumped together in a supercontinent he called Pangaea.
  • Over 200 million years, the continents had drifted apart. This was called continental drift theory.
  • But it was widely ridiculed as a mere hypothesis.
  • It was only in the 1960s, when technologies had developed that the validity of his theory was proved and further enhanced by McKenzie and Parker, through their theory of plate tectonics.
Source- Down to Earth 

More Related Current Affairs View All

15 Nov

Government issues guidelines to curb misleading ads by coaching centres

'The central Government issued new guidelines aimed at curbing misleading advertisements by coaching institutes, specifically prohibiting false promises such as "100 per cent selec

Read More

15 Nov

Janjatiya Gaurav Divas

'Every year on November 15th, Janjatiya Gaurav Divas is celebrated to honor the contributions of these communities, especially in India’s freedom struggle.' 5th November

Read More

15 Nov

Supreme Court’s order on mandatory accessibility standards

'A bench of the Supreme Court last week ordered the Union government to frame mandatory rules for ensuring the accessibility of public places and services to persons with disabilit

Read More

India’s First Ai-Driven Magazine Generator

Generate Your Custom Current Affairs Magazine using our AI in just 3 steps