Far out cosmology: how the Earth formed (Introduction)

by David Turell , Thursday, March 27, 2025, 17:49 (7 days ago) @ David Turell

A new study:

https://www.sciencedaily.com/releases/2025/03/250326154430.htm

"'This study is the first to demonstrate, using a physical model, that the first-order features of Earth's lower mantle structure were established four billion years ago, very soon after the planet came into existence," says lead author Faculty of Science Assistant Professor Charles-Édouard Boukaré in the Department of Physics and Astronomy at York.

"The mantle is the rocky envelopment that surrounds the iron core of rocky planets. The structure and dynamics of the Earth's lower mantle play a major role throughout Earth's history as it dictates, among others, the cooling of the Earth's core where the Earth's magnetic field is generated.

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"Boukaré's model is based on a multiphase flow approach that allows for capturing the dynamics of magma solidification at a planetary scale. Using his model, he studied how the early mantle transitioned from a molten to a solid state. Boukaré and his team were surprised to discover that most of the crystals formed at low pressure, which he says creates a very different chemical signature than what would be produced at depth in a high-pressure environment. This challenges the prevailing assumptions in planetary sciences in how rocky planets solidify.

"'Until now, we assumed the geochemistry of the lower mantle was probably governed by high-pressure chemical reactions, and now it seems that we need to account also for their low-pressure counterparts."

"Boukare says this work could also help predict the behaviour of other planets down the line.

"'If we know some kind of starting conditions, and we know the main processes of planetary evolution, we can predict how planets will evolve.'"

Comment: this is in the very early formation. Later on life appears and makes major transformations on Earth's surface, as previously discussed here : 2020-10-10, 19:09