A sliver of four-billion-year-old sea floor has offered a glimpse into the inner workings of an adolescent Earth. The baked and twisted rocks, now part of Greenland, show the earliest evidence of plate tectonics, colossal movements of the planet's outer shell. Until now, researchers were unable to say when the process, which explains how oceans and continents form, began. The unique find, described in the journal Science, shows the movements started soon after the planet formed. "Since the plate tectonic paradigm is the framework in which we interpret all modern-daygeology, it is important to know how far back in time it operated," said Professor Minik Rosing of the University of Copenhagen and one of the authors of the paper.
Sea floor is not normally preserved for more than 200 million years. Professor John Valley, a geologist at the University of Wisconsin, Madison described the work as "significant" and "exciting". "If these observations are substantiated it will be a significant line of new evidence indicating that plate tectonics was active and familiar as early as 3.8 million years ago," he said. "That really is an important conclusion." Plate tectonics is a geological theoryused to explain the observed large-scale motions of the Earth's surface. The relatively thin outer shell of the planet is composed of two layers: the lithosphere and the asthenosphere. Ancient pillow lavas are preserved in exquisite detail The lithosphere - made up of the outer crust and the top-most layer of the underlying mantle - is broken up into huge plates; seven major plates and several smaller ones.To view the rest of this article, please visit the source
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Posted on Friday, March 23 - 2007
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Posted on Wednesday, December 09 - 2009
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Concerns over a rise in sea level due to global warming have been prevalent in recent years, a new study has suggested that sea levels could rise from 0.75 to 1.9 meters before the turn of the 22ndcentury."A new scientific study warns that sea level could rise much faster than previously expected. Views : 168
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Tags Question mark, Natures Mysteries
Posted on Saturday, December 05 - 2009
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New fossil evidence has suggested that some land animals would have survived the end-Permian mass extinction 252 million years ago by moving to Antarctica to take advantage of the cooler climate there."The largest knownmass extinction in Earth"s history, about 252 million years ago at the end of the Permian Period, may have been caused by global warming. Views : 183
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Tags Evolution, Natures Mysteries
Posted on Tuesday, October 27 - 2009
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Evidence has been found to suggest that giant creatures such as the massive one-tonne titanoboa snake would have thrived in hot jungles millions of years ago with temperatures significantlywarmer than those seen today."Fossil boffins say that dense triple-canopy rainforests, home among other things to gigantic one-tonne boa constrictors, flourished millions of years ago in temperatures 3-5°C warmer than those seen today - as hot as some of themore dire global-warming projections." Views : 379
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Tags Nature, Natures Mysteries
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