[Rockhounds] New Study Rewrites Our Understanding of Earth’s Deep Carbon and Chlorine Cycles

[Kreigh Tomaszewski]

A recent study led by Macquarie University
<https://scitechdaily.com/tag/macquarie-university/> earth scientist Dr.
Chunfei Chen sheds new light on geological processes from up to three
billion years ago and marks a significant shift in the scientific
community’s understanding of the early Earth.

Recently published in the journal *Nature*, the research explores the
transformative effects of Earth’s gradual cooling on the deep cycling of
carbon and chlorine between the Earth’s surface and its interior.

“The cooling of the Earth has caused immense changes in the deep cycles of
both carbon and chlorine,” says Dr. Chen.

“Today, chlorine typically returns to the surface in volcanic gases, while
most carbon is trapped as solid carbonate at depths of hundreds of
kilometers; but until the Earth was about two-thirds of its present age,
the situation was the complete opposite.”

Magma dominated the Earth’s surface in the early period after the planet’s
formation, but as the planet gradually cooled, crustal plates around 100 km
thick formed on the surface, gliding over the mantle under the process of
plate tectonics.

As oceanic tectonic plates dive back into the mantle at subduction zones,
sediments lodged in troughs beneath the oceans may also have been pushed
into the mantle.

https://scitechdaily.com/unlocking-earths-ancient-secrets-new-study-rewrites-our-understanding-of-earths-deep-carbon-and-chlorine-cycles/