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!
PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target
22.05.2018 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy