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 Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Predicting unpredictability: Information theory offers new way to read ice cores

07.12.2016 | Earth Sciences

Sea ice hit record lows in November

07.12.2016 | Earth Sciences

New material could lead to erasable and rewriteable optical chips

07.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>