• Email Us: [email protected]
  • Contact Us: +1 718 874 1545
  • Skip to main content
  • Skip to primary sidebar

Medical Market Report

  • Home
  • All Reports
  • About Us
  • Contact Us

Main Explanation For The Rise Of Continents Challenged By New Study

May 8, 2023 by Deborah Bloomfield

The reason why continents mostly stand above sea level is believed to be that continental crust is lower in iron and more oxidized than oceanic crust. This makes continents more buoyant over the Earth’s mantle. The difference in composition is poorly understood, but a popular hypothesis suggested that garnet formation was key to this. Now, new experiments are calling that into question.

Work published five years ago proposed the crystallization of garnet as the crucial mechanism. The location of this event is the continental arc volcanoes, where oceanic crust sinks beneath continental crust. The idea is that garnet formation there removed non-oxidized iron from the magma – in one go, the magma that ended up on the continent was simultaneously poorer in iron and richer in oxidized minerals. A compelling explanation, but some scientists saw potential limitations that needed testing.

Advertisement

“You need high pressures to make garnet stable, and you find this low-iron magma at places where crust isn’t that thick and so the pressure isn’t super high,” senior author Elizabeth Cottrell, research geologist and curator of rocks at the Smithsonian’s National Museum of Natural History, said in a statement.

Cottrell’s team created garnet in the lab from molten rocks, trying to simulate what happens when these gems form in those places where the pressure is not super high. They placed the molten rock in special cylinders that could simulate 15,000 to 30,000 Earth atmospheres of pressure and got garnets out of them. They then looked at how much unoxidized iron was removed from the rocks. And it wasn’t enough to explain the composition of the continental crust.

“These results make the garnet crystallization model an extremely unlikely explanation for why magmas from continental arc volcanoes are oxidized and iron-depleted,” Cottrell continued. “It’s more likely that conditions in Earth’s mantle below continental crust are setting these oxidized conditions.”

The findings obviously bring back the crucial questions about why continents exist and what has caused their composition to be special.

Advertisement

“What is doing the oxidizing or iron depleting?” Cottrell asked. “If it’s not garnet crystallization in the crust and it’s something about how the magmas arrive from the mantle, then what is happening in the mantle? How did their compositions get modified?”

The team is now investigating whether oxidized sulfur could be oxidizing the iron, and therefore explain the discrepancy between continental and oceanic crust.

The findings were published in the journal Science.

Deborah Bloomfield
Deborah Bloomfield

Related posts:

  1. Kroger expects smaller decline in same-store sales on grocery demand
  2. Libya presidency council head plans to hold October conference
  3. Tikehau Capital aims for around 5 billion euros of assets dedicated to tackling climate change
  4. Think Your Country Is Hot On Abortion Rights? Think Again

Source Link: Main Explanation For The Rise Of Continents Challenged By New Study

Filed Under: News

Primary Sidebar

  • A Spinning Island Lake In Argentina Looms Out Of The Swamps Like An Eyeball
  • Mammals Have Evolved Into Ant Eaters 12 Times Since The Dinosaurs Went Extinct
  • Thieving Pulsar Spinning 592 Times A Second Reveals New Understanding Of Where Its X-Rays Come From
  • The Rise And Fall (And Lamentable Rise) Of The “Alpha Male” Myth
  • IFLScience The Big Questions: How Do Black Holes Shape The Universe?
  • North America’s Smallest Turtle Is The Cutest Thing You’ll Find In A Bog
  • “Unambiguous Signal” To Curb Emissions Now: Long-Lost Aerial Photos Reveal Evolution Of Antarctic Ice Shelf Collapse
  • 8 Children Have Been Born With 3 Biological Parents Each After Mitochondrial Transfer
  • First Known Observations Of Matter-Antimatter Asymmetry In Special Particle Decay
  • In 1973, NASA Sent Two Spiders Into Space To See If They Can Spin Webs – And They Learnt A Lot
  • Meet The Many Species Of Freaky Looking “Assassin Spiders” That Only Eat Other Spiders
  • Your Dog’s TV Preferences Might Reveal Their Personality
  • Some Human Gut Bacteria Can Absorb Harmful Toxic “Forever Chemicals” So They Can Be Pooped Out
  • You Could Float Through 10 Countries Before The World’s Most International River Spat You Out
  • Enormous Coronal Hole And Beast-Like Crawling Prominences Dazzle On The Active Sun
  • Dramatic Drone Footage Of Iceland’s Latest Volcanic Eruption Shows An Epic Scene From Hell
  • A Shrimp That Lives In A Tree? Indonesia’s Cyclops Mountains Are Home To Some Seriously Strange Wildlife
  • Is NASA’s Claim That Saturn Could Float On Water Really True?
  • Pangea Proxima: This Is What Planet Earth May Look Like 250 Million Years In The Future
  • The Story Of Dogxim, The Fox-Dog Hybrid That Shouldn’t Have Existed
  • Business
  • Health
  • News
  • Science
  • Technology
  • +1 718 874 1545
  • +91 78878 22626
  • [email protected]
Office Address
Prudour Pvt. Ltd. 420 Lexington Avenue Suite 300 New York City, NY 10170.

Powered by Prudour Network

Copyrights © 2025 · Medical Market Report. All Rights Reserved.

Go to mobile version