. 24/7 Space News .
SHAKE AND BLOW
Antarctic zircons tell story of early volcanism
by Staff Writers
Houghton MI (SPX) Nov 30, 2017


File image of zircon crystals.

Geoscientists from Michigan Technological University, University of Wisconsin Oshkosh and ETH Zurich have traced the age and chemical signatures stored in tiny zircon minerals to examine the recycling of carbon from the mantle to the surface through time.

A better understanding of these changes in carbon recycling help improve models about how the planet's early processes transitioned from the cold Snowball Earth with near-global ice cover into more temperate swings between ice ages and warming periods. The team's research will be published in Nature Geoscience next Monday.

"The geochemistry reflects a disequilibrium - and the Earth has to expel all of that to try to get back to equilibrium," says Chad Deering, one of the co-authors and an assistant professor of geology at Michigan Tech. "What we propose is that a series of events had to coincide to ultimately lead to the optimal conditions required to release an anomalous amount of carbon."

The chemical change is recorded on the scale of continents, but the details of that continent-building are locked in the layer-by-layer crystal structures of tiny zircons gathered from Antarctica. Some of the minerals are smaller than 100 microns, barely the width of an average human hair.

"We focused on looking at the trace elements in those zircons," Deering says. "There's a classification scheme that we use to determine the original rock type that the mineral grew in, which then tells us what kind of magma left that particular chemical signature of trace elements."

The ETH Zurich lab then used uranium-lead dating to determine how old the samples are. Given the dates and trace elements, what Deering and his team observed is a peak in carbon-emitting magma types that occurred between 500 to 700 million years ago during the Ediacaran period. What that means is that a significant amount of carbon was likely released.

Volcanoes emit a lot of carbon dioxide - some much more so than others. Alkaline volcanoes like Mount Etna in Italy and Mount Erebus in Antarctica dwarf the carbon output of other volcanos by 10 to 50 times. And it's the same type of volcanism that was identified in the zircons studied by Deering.

"Alkaline magmas are produced by melting just a little bit of the mantle," he explains, adding that while rare and small in volume, their importance is in the amount of carbon dioxide belted out and the special conditions they form under. "What happens as subduction occurs is that the mantle becomes 'polluted' with volatile material from the Earth's surface - water, carbon, sulfur."

The changes leading up to this significant event are slow - occurring over hundreds of millions of years - and have major consequences. As the Earth cools through time and the mantle becomes increasingly more polluted, it will eventually generate alkaline magma that can erupt at the surface.

The cooler subduction and mantle pollution can produce rocks known as blueschists, well-documented in the rock record during the Ediacaran period, along with alkaline volcanism.

Following the pulse of carbon-rich volcanism, atmospheric carbon dioxide spikes, which is also recorded in the carbon isotope record, accompanied by a warming period. All told, this series of events gave rise to the atmosphere and geological cycles that shaped the planet as it is today.

"To create a timeline, we needed to have dates on a significant number of zircons spanning many hundreds of millions of years," Deering says. "In essence, we discovered that throughout the Earth's history there was a particularly significant pulse of carbon emitted that immediately preceded the Cambrian explosion, the most important emergence of life that has yet to occur."

Gleaned from tiny zircons, the team used the chemical signatures of ancient volcanoes to establish that a series of fortunate events occurred as the oldest continents were constructed and materials recycled from the surface to eventually shape our modern carbon cycle.

Research paper

SHAKE AND BLOW
Clay mineral waters Earth's mantle from the inside
Hamburg, Germany (SPX) Nov 30, 2017
The first observation of a super-hydrated phase of the clay mineral kaolinite could improve our understanding of processes that lead to volcanism and affect earthquakes. In high-pressure and high-temperature X-ray measurements that were partly conducted at DESY, scientists created conditions similar to those in so-called subduction zones where an oceanic plate dives under the continental crust. ... read more

Related Links
Michigan Technological University
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
Does the Outer Space Treaty at 50 need a rethink

NASA to send critical science, instruments to Space Station

Can a magnetic sail slow down an interstellar probe

SSL Selected to Conduct Power and Propulsion Study for NASA's Deep Space Gateway Concept

SHAKE AND BLOW
Flat-Earther's self-launch plan hits a snag

SSTL ships CARBONITE-2 and Telesat's LEO-1 for PSLV launch

Aerojet Rocketdyne supports ULA Delta II launch of JPSS-1

Old Rivals India, China Nurture New Rivalry in Satellite Launch Business

SHAKE AND BLOW
Gadgets for Mars

Ice shapes the landslide landscape on Mars

Winds Blow Dust off the Solar Panels Improving Energy Levels

Previous evidence of water on Mars now identified as grainflows

SHAKE AND BLOW
Nation 'leads world' in remote sensing technology

China plans for nuclear-powered interplanetary capacity by 2040

China plans first sea based launch by 2018

China's reusable spacecraft to be launched in 2020

SHAKE AND BLOW
Need to double number of operational satellites: ISRO chief

Space Launch plans UK industry tour

Astronaut meets volcano

European Space Week starts in Estonia

SHAKE AND BLOW
New way to write magnetic info could pave the way for hardware neural networks

Device could reduce the carbon footprint of ethylene production

Researchers inadvertently boost surface area of nickel nanoparticles for catalysis

X-rays reveal the biting truth about parrotfish teeth

SHAKE AND BLOW
Mexico's Yucatan Peninsula reveals a cryptic methane-fueled ecosystem in flooded caves

Researchers prolong life by curbing common enzyme

First known interstellar visitor is an 'oddball'

Lava or Not, Exoplanet 55 Cancri e Likely to have Atmosphere

SHAKE AND BLOW
Pluto's hydrocarbon haze keeps dwarf planet colder than expected

Jupiter's Stunning Southern Hemisphere

Watching Jupiter's multiple pulsating X-ray Aurora

Help Nickname New Horizons' Next Flyby Target









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.