Massive Asteroid Impacts Triggered Early Plate Tectonics, Study Suggests

Modeling simulations and comparisons with lunar impact studies have revealed that following Earth’s accretion about 4.6 billion years ago, Earth-shattering impacts continued to shape the planet for hundreds of millions of years.

Although these events appear to have tapered off over time, Pilbara craton in Australia and Kaapvaal craton in South Africa suggest the Earth experienced a period of intense bombardment about 3.2 billion years ago (Archean Eon), roughly the same time the first indications of plate tectonics appear in the rock record.

This coincidence caused Macquarie University’s Dr. Craig O’Neill and colleagues to wonder whether these circumstances could be related.

“Modeling studies of the earliest Earth suggest that very large impacts — more than 186 miles (300 km) in diameter — could generate a significant thermal anomaly in the mantle,” Dr. O’Neill said.

Read full story here

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.