中国发现地球史上最大的超级火山
(2009-06-15 15:41:36)
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超级火山的定义是喷发量超过450立方公里的火山,有记载的大规模的超级火山喷发量达到1000立方公里以上,著名的例子是黄石公园火山,它的喷发毁灭半个美国; 类似规模的还有南亚的TOBA火山。喷发量达到4500立方公里的超级火山已属非常罕见。然而近期发现的中国峨眉山火山,喷发量达到50万立方公里,远远超过上述例子。这次火山爆发造成地球史上规模最大的一次生物大灭绝。相信这是本世纪自然科学的一项重大发现。
这项研究由英国LEEDS大学和武汉中国地质大学合作完成。
相关资料
美国权威期刊:史上生物大灭绝或因峨眉山大喷发(图)
[url]http://web.wenxuecity.com/BBSView.php?SubID=kxtw&MsgID=10218[/url]
Wiki: Supervolcano
[url]http://en.wikipedia.org/wiki/Supervolcano[/url]
Ancient volcano may have caused mass extinction
[url]http://www.physorg.com/news162738601.html[/url]
Volcanism, Mass Extinction, and Carbon Isotope Fluctuations in the Middle Permian of China
Paul B. Wignall,1,* Yadong Sun,2 David P. G. Bond,1 Gareth Izon,3 Robert J. Newton,1 Stéphanie Védrine,1 Mike Widdowson,3 Jason R. Ali,4 Xulong Lai,2 Haishui Jiang,2 Helen Cope,5 Simon H. Bottrell1
[url]http://www.sciencemag.org/cgi/content/abstract/324/5931/1179[/url]
The 260-million-year-old Emeishan volcanic province of southwest China overlies and is interbedded with Middle Permian carbonates that contain a record of the Guadalupian mass extinction. Sections in the region thus provide an opportunity to directly monitor the relative timing of extinction and volcanism within the same locations. These show that the onset of volcanism was marked by both large phreatomagmatic eruptions and extinctions amongst fusulinacean foraminifers and calcareous algae. The temporal coincidence of these two phenomena supports the idea of a cause-and-effect relationship. The crisis predates the onset of a major negative carbon isotope excursion that points to subsequent severe disturbance of the ocean-atmosphere carbon cycle.
1 School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
2 Faculty of Earth Sciences, China University of Geosciences, Wuhan, Hubei 430074, China.
3 Department of Earth and Environmental Science, The Open University, Milton Keynes MK7 6AA, UK.
4 Department of Earth Sciences, Pokfulam Road, University of Hong Kong.
5 Department of Bioengineering, University of Strathclyde, Wolfson Building, 106 Rottenrow, Glasgow G4 0NW, UK.