Hadean Protocrust

Prelims – Current events of national and international importance| World Geography.

Mains (GS I) – Geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.

Why in News?

New research suggests that Earth’s first crust, formed over 4.5 billion years ago.

• The Hadean protocrust is the name for the earth’s crust, its outermost layer when it first formed.
• Hadean Aeon - The term 'Hadean' denotes the initial geologic aeon of the planet.
• Conditions of Earth - During this period, approximately 200 million years after its formation, the Earth's surface was partially in a molten state and was frequently struck by extraterrestrial rocks.
• The surface was extremely hot and hellish, as numerous volcanoes erupted simultaneously.
• Formation of Crust - As the magma ocean began to cool, the initial fragments of the crust started to form.
• However, it remained somewhat unstable, with certain sections breaking away while new areas solidified.
• Plate Tectonics - The thicker parts of the crust slowly formed the first continents, which moved like plates on the asthenospheric mantle, a layer of hot, gooey rock going 400 km down.
• These plates began to converge, occasionally sliding past one another or submerging beneath each other.
• Over thousands of years, these tectonic movements have imprinted distinctive chemical signatures in the crust.
• Indeed, researchers have been able to trace the history of plate tectonics by examining these signatures.

Reference

The Hindu | What is the Hadean protocrust?