DOI: 10.1016/j.palaeo.2017.06.014
论文题名: High-frequency fluctuations in redox conditions during the latest Permian mass extinction
作者: Mettam C. ; Zerkle A.L. ; Claire M.W. ; Izon G. ; Junium C.J. ; Twitchett R.J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: East Greenland
; Fe speciation
; Ferruginous sea
; Palaeoenvironment
; Stable isotopes
英文摘要: New high-resolution geochemical and sedimentological data from Fiskegrav, East Greenland, reveal fluctuations in marine redox conditions associated with the final disappearance of bioturbating organisms during the latest Permian mass extinction (LPME). Sedimentological observations imply a transgressive episode, and associated geochemical evidence for decreasing oxygen availability and the establishment of persistently ferruginous (Fe2+-rich) conditions implies the shoreward migration of oxygen deficient waters. The long-term decline in dissolved oxygen (DO) availability could have been exacerbated by increasing water temperatures, reducing the solubility of oxygen and promoting thermal stratification. Mixing of the water column could have been further inhibited by freshwater influxes that could have generated salinity contrasts that reinforced thermal stratification. Enhanced runoff could also have increased the delivery of nutrients to the marine shelf, stimulating biological oxygen demand (BOD). During the transition to persistently ferruginous conditions we identify intervals of intermittent benthic meiofaunal recolonization, events that we attribute to small transient increases in DO availability. The mechanism controlling these fluctuations remains speculative, but given the possible centennial- to millennial-scale frequency of these changes, we hypothesise that the mid-latitude setting of Fiskegrav during the Late Permian was sensitive to changes in atmospheric circulation patterns, which may have influenced local precipitation and intermittently modulated some of the processes promoting anoxia. © 2017 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68091
Appears in Collections: 过去全球变化的重建
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作者单位: School of Earth and Environmental Science, and Centre for Exoplanet Science, University of St Andrews, KY16 9AL, UK; Dept. of Earth Science, Syracuse University, NY 13244-1070, USA; Dept. of Earth Science, Natural History Museum, London SW7 5BD, UK; Dept of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Recommended Citation:
Mettam C.,Zerkle A.L.,Claire M.W.,et al. High-frequency fluctuations in redox conditions during the latest Permian mass extinction[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01