DOI: 10.1016/j.palaeo.2014.02.016
论文题名: A new model for the Kellwasser Anoxia Events (Late Devonian): Shallow water anoxia in an open oceanic setting in the Central Asian Orogenic Belt
作者: Carmichael S.K. ; Waters J.A. ; Suttner T.J. ; Kido E. ; DeReuil A.A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 399 起始页码: 394
结束页码: 403
语种: 英语
英文关键词: Central Asian Orogenic Belt
; Eutrophication
; Island arc
; Kellwasser
; Late Devonian
英文摘要: The Frasnian-Famennian mass extinction event devastated tropical marine ecosystems and ranks in the top six in taxonomic and ecological severity. The close stratigraphic association between the extinction and the Kellwasser Anoxia Events support a link between oceanographic anoxia and extinction. The Upper and Lower Kellwasser horizons have been identified in epicontinental and basinal settings in Laurussia, Gondwana, Siberia, and South China. The Hongguleleng Formation (Late Devonian) in northwestern Xinjiang, China, contains both the Frasnian-Famennian boundary and the rebound from the Frasnian-Famennian extinction event in a highly fossiliferous shallow marine setting associated with a Devonian oceanic island arc complex (part of the Central Asian Orogenic Belt, or CAOB). Here we show that the Hongguleleng Formation also records the Upper Kellwasser Anoxia Event through analysis of multiple geochemical proxies. In contrast to previous studies asserting that the Kellwasser Events were restricted to epicontinental seaways and basins, our results indicate that it occurred not only along the shallow continental margins of the closing Rheic Ocean, but also in shallow water in the open oceanic part of Paleotethys. Previous explanations for the Kellwasser Events from epicontinental margins and basins call for the migration of deep anoxic bottom water into shallow water environments as a kill mechanism for shallow marine ecosystems or attribute it to sea level rise and subsequent stagnation. There is no evidence that the Devonian oceans completely overturned during the Kellwasser Events; similarly, many transgressive events in the Devonian are not associated with black shales. We therefore suggest an alternative mechanism for the Kellwasser Events based on new evidence from the CAOB, where anoxia is driven by episodic eutrophication of surface waters. © 2014 Elsevier B.V.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69421
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geology, Appalachian State University, Boone, NC 28608, United States; Karl-Franzens-University of Graz, Institute for Earth Sciences (Geology and Paleontology), Heinrichstrasse 26, A-8010 Graz, Austria; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, United States
Recommended Citation:
Carmichael S.K.,Waters J.A.,Suttner T.J.,et al. A new model for the Kellwasser Anoxia Events (Late Devonian): Shallow water anoxia in an open oceanic setting in the Central Asian Orogenic Belt[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,399