气候变化领域集成服务门户(CCPortal): Global-ocean redox variations across the Smithian-Spathian boundary linked to concurrent climatic and biotic changes

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DOI	10.1016/j.earscirev.2018.10.012
	Global-ocean redox variations across the Smithian-Spathian boundary linked to concurrent climatic and biotic changes
	Zhang F.; Algeo T.J.; Cui Y.; Shen J.; Song H.; Sano H.; Rowe H.D.; Anbar A.D.
发表日期	2019
ISSN	00128252
起始页码	147
结束页码	168
卷号	195
英文摘要	The Smithian-Spathian boundary (SSB) was an interval characterized by a major global carbon cycle perturbation, climatic cooling from a middle/late Smithian boundary hyperthermal condition, and a major setback in the recovery of marine necto-pelagic faunas from the end-Permian mass extinction. Although the SSB has been linked to changes in oceanic redox conditions, key aspects of this redox variation (e.g., duration, extent, and triggering mechanisms) and its relationship to coeval climatic and biotic changes remain unresolved. Here, we report a high-resolution middle Smithian to middle Spathian U isotope (δ238U) record based on marine carbonates of the Zuodeng (South China) and Jesmond (British Columbia) sections to investigate the timing and global extent of ocean-redox variation across the SSB. Our δ238U record reveals values similar to or slightly heavier than modern seawater (-0.39‰) during the middle Smithian, a rapid negative shift to highly negative values during the early late Smithian, a positive shift at the SSB, and a rapid shift back to more negative values in the early-middle Spathian. A simple U-isotope mass balance modeling suggests that the global area of anoxic seafloor expanded strongly during the late Smithian and the early-middle Spathian (covering ~11% of total seafloor area), but that it contracted sharply during the SSB (~2%). The redox pattern documented by our δ238U record shows a good first-order correspondence to tropical sea-surface temperature (SST) data for the Smithian-Spathian. In particular, peak anoxia coincided with the middle/late Smithian boundary hyperthermal event, and diminished anoxia with a pronounced decline in SSTs at the SSB. The temporal correlation between anoxia and low biodiversity levels of many marine clades (e.g., conodonts and ammonoids) during the late Smithian indicates that oceanic anoxia may have played a role in the SSB biocrisis. © 2018 Elsevier B.V.
关键词	British Columbia Early Triassic oceanic anoxia Smithian/Spathian boundary South China U isotopes
英文关键词	anoxia; biotic factor; climate variation; global ocean; paleoceanography; redox conditions; Triassic; uranium isotope; British Columbia; Canada; China; Ammonoidea
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203607
作者单位	School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-6004, United States; Department of Geology and Geophysics, Yale University, New Haven, CT 06511, United States; Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013, United States; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei 430074, China; Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, United States; Department of Earth and Planetary Sciences, Kyushu University, Fukuoka, 812-8581, Japan; Bureau of Economic Geology, The University of Texas at Austin, University Station, Austin, TX 78713-8924, United States; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
推荐引用方式 GB/T 7714	Zhang F.,Algeo T.J.,Cui Y.,et al. Global-ocean redox variations across the Smithian-Spathian boundary linked to concurrent climatic and biotic changes[J],2019,195.
APA	Zhang F..,Algeo T.J..,Cui Y..,Shen J..,Song H..,...&Anbar A.D..(2019).Global-ocean redox variations across the Smithian-Spathian boundary linked to concurrent climatic and biotic changes.Earth Science Reviews,195.
MLA	Zhang F.,et al."Global-ocean redox variations across the Smithian-Spathian boundary linked to concurrent climatic and biotic changes".Earth Science Reviews 195(2019).