Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers detect hint of oxygen 50 to 100 million years earlier than first believed

01.10.2007
UCR part of teams from 5 research universities that analyzed Australian drill core for evidence of oxygen in Earth's early atmosphere

Two teams of scientists, including three researchers from UC Riverside, report that traces of oxygen appeared in Earth’s atmosphere roughly 100 million years before the “Great Oxidation Event” 2.4 billion years ago. The Great Oxidation Event is when most geoscientists think atmospheric oxygen rose sharply from very low levels and set the stage for animal life that followed almost two billion years later.

Analyzing layers of sedimentary rock in a kilometer-long core sample they retrieved in 2004 from the Hamersley Basin in Western Australia, the researchers found evidence for the presence of a small but significant amount of oxygen 2.5 billion years ago in the oceans and likely also in Earth’s atmosphere.

Because the core was recovered from deep underground, it contains materials untouched by the atmosphere for billions of years. After retrieval, the scientists sliced the core longitudinally for analysis.

Study results appear in a pair of papers in tomorrow’s issue of Science.

The UCR contribution:

Geochemists Timothy Lyons, Steven Bates, and Clinton Scott of the UCR Department of Earth Sciences — working with teams from Arizona State University and the universities of Maryland, Washington, and Alberta — generated elemental and isotopic data that provide indirect, or proxy, evidence for the evolving atmosphere and its relationship to the early evolution of life.

“This is the earliest convincing record for an ephemeral accumulation of oxygen in the biosphere before its irreversible rise beginning 2.4 billion years ago,” said Lyons, a professor of biogeochemistry.

Scott, a graduate student working with Lyons, used metals in the ancient ocean—now trapped in sedimentary rocks—as proxies for the amount of oxygen in the early ocean and atmosphere. His doctoral research provided a baseline for the Australian samples, showing that the 2.5 billion-year old rocks look more like those from younger times when oxygen was higher in the atmosphere.

These results revealed to the UCR geochemists and their colleagues at Arizona State University that oxygen increased significantly but briefly 100 million years before its permanent place in Earth’s atmosphere.

Working principally with colleagues at the University of Maryland, Bates, a research associate, and Lyons analyzed sulfur present in the Australian rocks as another fingerprint of oxygen concentrations at Earth’s surface. Their analysis of the sulfur also confirmed that the world changed briefly but importantly 2.5 billion years ago, presaging the life-affirming oxygenation of the atmosphere 100 million years later.

“We were surprised to see evidence of increasing oxygen in rocks so old,” Lyons said. “And the fact that two independent lines of evidence point in the same direction suggests that Earth’s most dramatic shift in atmospheric composition and its relationship to the evolution of life began earlier and was more complex than most imagined.”

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Earth Sciences:

nachricht NASA examines Peru's deadly rainfall
24.03.2017 | NASA/Goddard Space Flight Center

nachricht Steep rise of the Bernese Alps
24.03.2017 | Universität Bern

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>