Emeishan Trapp

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The Emeishan-Trapp is a flood basalt in southern China, the center of which is in the Chinese province of Sichuan . In the Anglo-American language area it is also known as Permian Emeishan Large Igneous Province (translated about Permian Magmatic Greater Province of Emeishan ). The basalt deposits extend over an area of ​​250,000 km² and are deformed in a complicated way by tectonic processes in the Mesozoic and Cenozoic and displaced from their originally horizontal position.

Like other occurrences of Trapp , the Emeishan Trapp is composed of many layers of volcanic rock deposited as lava from extensive volcanic eruptions. The eruptions began about 260 million years ago and are attributed to a plume . The basalts are accompanied by countless intrusions .

Although the Emeishan trap was nowhere near as large as the Siberian trap , which was geologically somewhat younger at 251 million years ago , it is associated with the mass extinction at the end of the Middle Permian ( Guadalupian ) due to the assumed ecological effects . Because of this temporal coincidence, the Emeishan Trapp is part of the larger scientific debate about the causes of mass extinctions in Earth's history. The temporal coincidence served as an argument - among others, this was supported by Vincent Courtillot - for the theory that volcanism is the main cause of mass extinction. Opponents of this theory assume that the cause of the mass extinction is impact events caused by the impact of a meteorite or comet . Some of them attribute volcanic events that led to the formation of flood basalts such as the Emeishan Trapp or the Dekkan Trapp to such meteorite impacts. However, the theory of a meteorite impact as the cause of the Emeishan Trapp is highly controversial.

Individual evidence

  1. ↑ Ching-Hua Lo, Sun-Lin Chung, Tung-Yi Lee, Genyao Wu: Age of the Emeishan Flood Magmatism and Relations to Permian-Triassic Boundary Events. Earth and Planetary Science Letters, Vol. 198, pp. 449 - 458, 2002 (PDF, 650 kB)
  2. ↑ Bin He, Yi-Gang Xu, Sun-Ling Chungc, Long Xiaoa, Yamei Wang: Sedimentary evidence for a rapid kilometer-scale crustal doming prior to the eruption of the Emeishan flood basalts. Earth and Planetary Science Letters, Vol. 213, pp. 391-405, 2003, ( doi : 10.1016 / S0012-821X (03) 00323-6 )
  3. ↑ Hey Bin; Yi-Gang Xu; Xiao-Long Huang; Zhen-Yu Luo; Yu-Ruo Shi; Qi-jun yang; Song-Yue Yu: Age and duration of the Emeishan flood volcanism, SW China: Geochemistry and SHRIMP zircon U-Pb dating of silicic ignimbrites, post-volcanic Xuanwei Formation and clay tuff at the Chaotian section. Earth and Planetary Science Letters, Vol. 255, pp. 306–323, 2007 ( doi : 10.1016 / j.epsl.2006.12.021 )
  4. ↑ Shu-zhong Shen, James L. Crowley, Yue Wang, Samuel A. Bowring, Douglas H. Erwin, Peter M. Sadler et al .: Calibrating the End-Permian Mass Extinction. Science, 2011, doi : 10.1126 / science.1213454
  5. ↑ Mei-Fu Zhou, John Malpas, Xie-Yan Song, Paul T. Robinson, Min Sun, Allen K. Kennedy, C. Michael Lesher, Reid R. Keays: A temporal link between the Emeishan large igneous province (SW China) and the end-Guadalupian mass extinction. Earth and Planetary Science Letters, Vol. 196, No. 3–4, pp. 113–122, 2002 ( doi : 10.1016 / S0012-821X (01) 00608-2 )
  6. ↑ Adrian P. Jones; David G. Price; Paul S. DeCarli; Richard Clegg: Impact Decompression Melting: A Possible Trigger for Impact Induced Volcanism and Mantle Hotspots? In: C. Koeberl and F. Martinez-Ruiz (eds.): Impact markers in the Stratigraphic Record . Springer Verlag, Berlin 2003, ISBN 3-540-00630-3 , pp. 91-120 ( mantleplumes.org [PDF]).