Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Geologist’s Discovery May Unlock Secrets to Start of Life on Earth

03.07.2002


Scientist continues to build case for origin of plate tectonics



A Saint Louis University geologist has unearthed further evidence in his mounting case that shifting of the continents -- and perhaps life on Earth -- began much earlier than many scientists believe.

Tim Kusky, a professor of Earth and atmospheric sciences, has discovered the world’s first large intact pieces of oceanic mantle from the planet’s earliest period, the Archean. The nearly mile-long section of rock, which is billions of years old, may hold clues as to when life developed on the planet. The major finding was reported today in the July issue of GSA-Today -- the premier journal of the Geological Society of America.


Working with colleagues from Peking University, Kusky uncovered the rare find at a site near the Great Wall where last year the team discovered the planet’s oldest complete section of oceanic crust. Reported in Science, their work recently was heralded by the Chinese government as one of the most significant scientific findings of 2001.

This latest discovery may prove even more remarkable. For years, scientists have longed to find large pieces of the planet’s deep interiors. But until now, they’ve had to rely on only tiny fragments to study. Formed tens of kilometers below the ancient sea floor, this new discovery’s massive mantle rocks are preserved in a highly faulted belt 100 kilometers long. Unlike the sea floor samples Kusky found last year, the mantle rocks preserve 2.5 billion-year-old minerals that hold clues to the origin of plate tectonics. The minerals, including an unusual type of chromite deposit only known from deep ocean floor rocks appear to have been deformed at extremely high temperatures before they were completely crystallized by volcanic

This shows that the mantle rocks were flowing away from the ridges on the oceanic floor, evidence that the continents began shifting more than 500 million years earlier than now widely believed. Because the discovery shows that the plates were moving in that early period, these findings could have a more far-reaching effect on theories related to the development of life on the planet. Just when single-celled organisms evolved into more complex organisms has been contested for years. Because hot volcanic vents on the sea floor may have provided the nutrients and temperatures needed for life to flourish, Kusky said it’s possible that life developed and diversified around these vents as the plates started stirring.

Kusky and Peking University’s J.H. Li have initiated a series of studies on the section of ancient mantle and it’s minerals aimed at understanding the conditions of the Earth 2.5 billion years ago. Their work is being funded by U.S. National Science Foundation, the Chinese National Natural Science Foundation, Saint Louis University and Peking University. The Chinese government also has dedicated a natural geologic park at the site of the discovery.

Saint Louis University is a leading Catholic, Jesuit, research institution ranked among the top 50 national, doctoral universities as a best value by U.S. News & World Report. Founded in 1818, the University strives to foster the intellectual and spiritual growth of its more than 11,000 students through a broad array of undergraduate, graduate and professional degree programs on campuses in St. Louis and Madrid, Spain.

Clayton Berry | EurekAlert!
Further information:
http://www.geosociety.org/
http://www.eas.slu.edu/People/TMKusky/

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>