Researchers discover missing ingredient from Earth's continental crust

February 14, 2018, Curtin University

Researchers from Curtin University have identified a missing ingredient in the composition of the continental crust, opening up a new chapter in the Earth's geological history.

The paper, published in Nature Communications, sheds new light on an inconsistency that until now had baffled experts because the high levels of nickel and in the continental crust could not be explained by current models of continental crust formation.

Lead Curtin researcher Dr. Andreas Beinlich, from the School of Earth and Planetary Sciences, said models explaining the of the continental crust lacked one important ingredient, known as ultramafic rock, which has eroded over time thus contributing to the continental crust composition and formation.

"Our current understanding is that the continental crust formed only by magmatic processes, meaning that igneous rocks formed by the crystallization of melt and eventually lumped together to form the crust," Dr. Beinlich said.

"This theory is certainly true, but other processes are also important and contribute to the formation of the continental crust and its chemical evolution.

"Our research was able to explore a new theory that the chemical composition of the crust can be more fully explained by the addition of weathered and eroded ultramafic rock, which is rich in magnesium, nickel and chromium but poor in silica."

Dr. Beinlich explained that the team, made up of international researchers, was able to determine this by analysing rock samples collected in Western Australia, Norway and Canada.

"We were able to determine that the amount of eroded rock required for compensating the nickel and chromium imbalance is small but still has a distinct effect on the of the Earth's crust," Dr. Beinlich said.

"Our research indicates that the transfer of nickel and chromium from the rock to the continental crust had to occur through weathering and erosion, essentially driven by chemical reactions between rocks and fluids including ocean water, rain water and ground water.

"Considering these fluid- reactions as a process that contributes to the formation of the offers a new explanation to understanding the formation of the Earth's and its geological history."

Explore further: Continental crust model illuminates processes that took place three to four billion years ago

More information: Andreas Beinlich et al. Peridotite weathering is the missing ingredient of Earth's continental crust composition, Nature Communications (2018). DOI: 10.1038/s41467-018-03039-9

Related Stories

Questions of continental crust

November 27, 2014

Geological processes shape the planet Earth and are in many ways essential to our planet's habitability for life. One important geological process is plate tectonics – the drifting, colliding and general movement of continental ...

How continents were recycled

August 23, 2017

Plate tectonics shape the Earth's dynamic surface. But when did these dynamics first emerge? And will the present-day continents last forever?

Earth's first example of recycling—its own crust

March 16, 2017

Rock samples from northeastern Canada retain chemical signals that help explain what Earth's crust was like more than 4 billion years ago, reveals new work from Carnegie's Richard Carlson and Jonathan O'Neil of the University ...

Recommended for you

'Chameleon' ocean bacteria can shift their colors

February 21, 2018

Cyanobacteria - which propel the ocean engine and help sustain marine life - can shift their colour like chameleons to match different coloured light across the world's seas, according to research by an international collaboration ...

New study brings Antarctic ice loss into sharper focus

February 21, 2018

A NASA study based on an innovative technique for crunching torrents of satellite data provides the clearest picture yet of changes in Antarctic ice flow into the ocean. The findings confirm accelerating ice losses from the ...

Stable gas hydrates can trigger landslides

February 21, 2018

Like avalanches onshore,many processes cause submarine landslides. One very widespread assumption is that they are associated with dissociating gas hydrates in the seafloor. However, scientists at GEOMAR Helmholtz Centre ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.