Clues from meteorite to Earth’s mantle

• Study of the Kamargaon meteorite by researchers from the Indian Institute of Technology (IIT) Kharagpur.
• The study has now shown that by studying this meteorite and its minerals we may find new clues about the Earth’s lower mantle.

Key points:

• Previous studies had noted that the Kamargaon meteorite contains minerals such as olivine, pyroxene, plagioclase and chromite.
• Olivine is also found in Earth's upper mantle.
• It is known to break down into bridgmanite and magnesiowustite in Earth’s lower mantle conditions.
• This breaking down is an important reaction that controls the physical and chemical properties of the Earth's interior.
• When materials are transported to the lower mantle by convection or subduction, there would be high-temperature conditions in the lower mantle that would cause this dissociated reaction.
• The results suggest what processes and reactions may be involved in the formation of Earth’s lower mantle.

Meteorites:

• A meteorite is a rock that falls to Earth from space.
• Meteorites are rocks, but they are not like Earth rocks.

Kamargaon meteorite:

• In November 2015, a meteorite fell near the town of Kamargaon in Assam, India.
• The meteorite originated in the asteroid belt between Mars and Jupiter and was sucked in by Earth’s gravity.

• Based on its mineral composition, it was classified as a chondrite, a variety of stony meteorites.
• It is a shocked meteorite, which means that the meteorite has gone through high-pressure and high-temperature conditions.