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The Postdoctoral Detective of Rice University is part of a new journal Nature that accredits the theories of the Earth's atmosphere 1.4 billion years ago [19659002] Rice, Justin Hayles and his colleagues, led by Peter Crockford. at McGill University in Montreal, badyzed samples from an old Canadian lake bed that revealed abnormal isotopes of oxygen included in sulfate deposits. The researchers found that the planet's gross primary production – a measure of processes like photosynthesis – was a small fraction of modern levels during a part of the Proterozoic known to researchers. "The Boring Billion" because of the environmental and evolutionary stability of the planet.
"The Boring Billion is boring because it seemed for a long time that nothing remarkable was happening on the surface of the Earth, but the evolution of the Earth. Its surface has continued," he said. said Hayles.
Hayles, a postdoctoral fellow at the National Science Foundation, did the job as a Ph.D. student at the Louisiana State University. He joined Rice Lab Laurence Yeung, Assistant Professor of Earth Sciences, Environment and Planets, two years ago.
Hayles' badysis with specialized mbad spectrometry equipment was part of the core badysis. "When the project started, we were just looking at what sulphates looked like through the Earth's history," he said. "In the process, we badyzed this set of samples and found an anomaly."
This anomaly was an unexpected amount of oxygen-17, one of three stable isotopes of oxygen. "It was shocking because we thought that this anomaly could only exist when atmospheric concentrations of carbon dioxide are extremely high, such as during a" snowball event "of the Earth," he said. Hayles. "It turns out that this condition is not necessary if the concentrations of atmospheric oxygen (O2) and bioproductivity are much lower than today."
As oxygen is very reactive, it combines easily with sulphides in what was then a lake at Sibley. Basin. "When you form sulphate from sulphide, you get a little O2 incorporated," he said. "This is preserved as a capsule of the ancient atmosphere, so it contains Proterozoic oxygen, 1.4 billion years ago.
The researchers suggested that their discovery is the oldest direct measurement of isotopes of atmospheric oxygen, taken at a time when microorganisms, including bacteria and algae, were beginning to increase photosynthetic production. but had not yet reached the fertile period that triggered a second "episode of oxygenation".
"It has been suggested for several decades that the composition of the atmosphere has varied considerably over time," said Crockford, now a postdoctoral fellow at Princeton. "We provide unequivocal evidence that the atmosphere has changed dramatically over time. it was indeed very different 1.4 billion years ago. "
The researchers said their finding could help in the search for clues about life on others planets, world versus modern Earth, "said Hayles." The atmosphere contained only a small amount of oxygen and the environment was undoubtedly much hotter. " Knowing how successful microbial life is is telling us what to expect on a hypothetical planet with a similar environment, "he said, if Mars was sufficiently similar to Earth and the right material was found on Earth, this technique could provide evidence similar. "
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Scientists from McGill University, Louisiana State University, Lakehead University, Weizmann Institute of Sciences in Israel, Peking University, l & # 39; Yale University, Princeton University and the University of California, Riverside participated in the study.
The research was supported by the Natural Sciences and Engineering Research Council of Canada. Quebec-Nature and Technologies and the University of Colorado Boulder.
Read the summary at http: // dx.
This press release can be viewed online at l 39. address http: // news.
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Located on a 300 acre wooded campus in Houston, Rice University is consistently ranked among the top 20 universities in the country by US News & World Report. Rice has highly respected schools of architecture, business, continuing education, engineering, social sciences, music, natural sciences and social sciences and is home to the Baker Institute. for Public Policy. With 3,970 undergraduate students and 2,934 graduate students, the ratio of undergraduate students per professor is slightly less than 6 to 1. Its network of residential colleges builds close bonds and lasting friendships, a Reasons why Rice is ranked # 1 for quality of life and for many interactions between running and clbad and # 2 for the happiest students. Rice is also considered the best value among private universities by Kiplinger's Personal Finance. To read "What they say about Rice," go to http://tinyurl.com.
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