DOI: 10.1016/j.palaeo.2015.03.036
论文题名: Loss of the sedimentary mixed layer as a result of the end-Permian extinction
作者: Hofmann R. ; Buatois L.A. ; MacNaughton R.B. ; Mángano M.G.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 428 起始页码: 1
结束页码: 11
语种: 英语
英文关键词: Bioturbation
; Ecosystem function
; Mass extinction
; Triassic
英文摘要: The end-Permian mass extinction resulted in the most dramatic degradation of marine bottom communities during the Phanerozoic. One result of this extinction was the long-recognized, extreme reduction in bioturbation of the Early Triassic seafloor. Several lines of evidence (i.e., preferential preservation of epifaunal and very shallow-tier infaunal trace fossils; paucity of mid- and deep-tier trace fossils; absence of mottled bioturbation textures; dominance of cohesive substrates; widespread occurrence of microbially induced sedimentary structures in open-marine environments; ecological composition of Early Triassic communities) show that the reduction in bioturbation was so extreme that the sedimentary mixed layer was eradicated at an interregional scale for the only time since it was established in the early Palaeozoic. The consequences of this for ecosystem function and geochemical cycling must have been profound and yet they have received little consideration. Biogenic mixing of sediments is fundamental to geochemical cycling in extant marine ecosystems, and it also governs ecologically limiting factors such as nutrient fluxes, benthic primary production, and availability of ecospace. The collapse of biogenic sediment mixing during the Early Triassic must have affected geochemical properties of sediments and the seawater, as reflected in the geologic record of the sulphur cycle. Additionally, many of the proxies traditionally used to infer Early Triassic seawater anoxia may rather reflect poor sediment oxygenation arising from the extinction of bioturbators. Because of its impact on seawater and sediment chemistry, the loss of the mixed layer may have been an important, but hitherto little-considered constraint on the recovery from the end-Permian mass extinction. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68937
Appears in Collections: 过去全球变化的重建
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作者单位: Paläontologisches Institut und Museum, Universität Zürich, Karl Schmid-Strasse 4, Zürich, Switzerland; Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, Canada; Geological Survey of Canada (Calgary), Natural Resources Canada, 3303-33 Street NW, Calgary, AB, Canada
Recommended Citation:
Hofmann R.,Buatois L.A.,MacNaughton R.B.,et al. Loss of the sedimentary mixed layer as a result of the end-Permian extinction[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,428