Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research proposes new theories about nature of Earth's iron

20.03.2017

Isotopic anomalies suggest formation of core may not explain planet's composition

New research challenges the prevailing theory that the unique nature of Earth's iron was the result of how its core was formed billions of years ago.


This artist's concept shows a high-speed collision in the early stages of planetary formation.

Credit: NASA/JPL-Caltech

The study opens the door to competing theories about why levels of certain heavy forms of iron, known as isotopes, are higher on Earth than in other bodies in the solar system. The prevailing view attributes the Earth's anomalous iron composition to the formation of the planet's core.

But the study published Feb. 20 in Nature Communications suggests that the peculiar iron's isotopic signature developed later in Earth's history, possibly created by a collision between Earth and another planetary body that vaporized the lighter iron isotopes, or the churning of Earth's mantle, drawing a disproportionate amount of heavy iron isotopes to Earth's crust from its mantle.

Iron is one of the most abundant elements in the solar system, and understanding it is key to figuring out how Earth and other celestial bodies formed. The researchers compared the ratio of the heavier iron isotope Fe-56 to the lighter Fe-54 for Earth and extraterrestrial rocks, including those from the moon, Mars and ancient meteorites. They found that the ratio is significantly higher for Earth rocks than for extraterrestrial rocks, all of which have an identical ratio. Their research attempts to explain how that happened.

"The Earth's core formation was probably the biggest event affecting the Earth's history," said Jung-Fu Lin, professor of geosciences at the University of Texas at Austin and co-author of the paper. "In this study we say that there must be other origins than the Earth's formation for this iron isotopic anomaly."

Co-author Nicolas Dauphas, the Louis Block Professor of Geophysical Sciences at the University of Chicago, called the research groundbreaking "because of the synthesis of the materials analyzed, the technique to take the measurements and the data treatment."

The authors recreated the high pressure that characterized the conditions on Earth during the formation of its core. To do this, the researchers used a diamond anvil cell--a device capable of recreating pressures that exist deep inside planets--and were able to synthesize processes that would not be discernible otherwise.

"The diamond anvil cell has been used in this way before, but the difficulty is getting correct numbers," Dauphas said. "That requires great care in data acquisition and treatment because the signal the diamond anvil gives off is very small. One has to use sophisticated mathematical techniques to make sense of the measurements, and it took a dream team to pull this off."

The experiment sought to show that the high levels of heavy iron isotopes in Earth's mantle likely occurred during the formation of Earth's core. But the measurements show that it does not work, "so the solution to this mystery must be sought elsewhere," Dauphas said.

More research is needed to understand the core's formation and the reasons for Earth's unique iron isotopic signature.

###

The team included researchers from the University of Chicago, Argonne National Laboratory, Sorbonne University in France, Museum National d'Histoire Naturelle in France, the Center for High Pressure Science and Technology Advanced Research in China and the University of Illinois at Urbana-Champaign.

Citation: "Iron isotopic fractionation between silicate mantle and metallic core at high pressure," in Nature Communications, Feb. 20, 2017, by Jin Liu, Nicolas Dauphas, Mathieu Roskosz, Michael Y. Hu, Hong Yang, Wenli Bi, Jiyong Zhao, Esen E. Alp, Justin Y. Hu and Jung-Fu Lin. DOI: 10.1038/ncomms14377

Media Contact

Greg Borzo
gborzo@comcast.net
773-702-8366

 @UChicago

http://www-news.uchicago.edu 

Greg Borzo | EurekAlert!

More articles from Earth Sciences:

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>