气候变化领域集成服务门户(CCPortal): The Mid-Ludfordian (late Silurian) Glaciation: A link with global changes in ocean chemistry and ecosystem overturns

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DOI	10.1016/j.earscirev.2021.103652
	The Mid-Ludfordian (late Silurian) Glaciation: A link with global changes in ocean chemistry and ecosystem overturns
	Frýda J.; Lehnert O.; Joachimski M.M.; Männik P.; Kubajko M.; Mergl M.; Farkaš J.; Frýdová B.
发表日期	2021
ISSN	00128252
卷号	220
英文摘要	The present study reviews the main geochemical, sedimentological, and paleontological events associated with one of the largest perturbations in the Phanerozoic carbon cycle, the Mid-Ludfordian Carbon Isotope Excursion (MLCIE), which is globally documented in late Silurian marine successions. Climate changes associated with the MLCIE are not yet well documented in contrast to most other Silurian CIEs. We report seawater surface temperature changes across the entire MLCIE using δ18Oapatite records of conodonts originating from different regions located in temperate as well as tropical paleolatitudes. Significant positive δ18Oapatite excursions (up to 3.8‰) measured in temperate-water areas of the Prague Basin and Carnic Alps (peri-Gondwana) as well as in the tropical areas of Baltica (Laurussia) and Australia (Gondwana) provide evidence for significant global cooling during the MLCIE. The marked cooling of sea surface temperatures, coupled with a significant eustatic sea-level fall recorded on all corresponding paleocontinents, point to a major glaciation in polar and subpolar Gondwana which is denominated here as the “Mid-Ludfordian Glaciation”. The onset of rapid cooling in the Prague Basin (peri-Gondwana) is preceded by the deposition of shales enriched in redox-sensitive trace metals suggesting that anoxic/euxinic waters expanded on the deeper carbonate shelf just before the MLCIE. The coincidence of culmination of the anoxic event (named here as the Siluricus Ocean Anoxic Event) with the Lau/Kozlowskii extinction events is documented for the first time outside of the Laurussian epeiric basins. Widespread oxygen-deficient conditions are interpreted to have been stressful to shelfal ecosystems and may have been a major cause of the extinctions. The mid-Ludfordian glacio-eustatic sea-level fall caused a reduction of shelf habitats culminating in a lower faunal diversity and a change in the structure of faunal communities. The observed positive δ18Oapatite excursion is tightly coupled to δ13C and δ34S anomalies documented from temperate (peri-Gondwana) as well as tropical (Laurussia) paleolatitudes. The δ18Oapatite data complete the Silurian seawater temperature curve and show evidence that one of the largest positive carbon isotope anomalies (MLCIE) of the Phanerozoic was preceded by a widespread anoxic event and tightly linked with a climate cooling event as documented as well for most other Silurian CIEs. © 2021
关键词	Anoxic event Climate change Extinction Lau/Kozlowskii Bioevent Ludfordian glaciation Silurian
英文关键词	anoxic conditions; climate variation; extinction; glaciation; glacioeustacy; overturn; paleoclimate; paleontology; sedimentology; Silurian; water chemistry; Czech Republic; Prague Basin
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/204022
作者单位	Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6, Suchdol, 165 21, Czech Republic; Czech Geological Survey, Klárov 3/131, Prague 1, 118 21, Czech Republic; GeoZentrum Nordbayern, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Schloßgarten 5, Erlangen, D-91054, Germany; Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China; Tallinn University of Technology, Institute of Geology, Ehitajate tee 5, Tallinn, 19086, Estonia; Centre of Biology, Geosciences and Environmental Sciences, Faculty of Education, University of West Bohemia, Klatovská 51, Plzeň, 30619, Czech Republic; Metal Isotope Group, Department of Earth Sciences, University of AdelaideSA 5005, Australia
推荐引用方式 GB/T 7714	Frýda J.,Lehnert O.,Joachimski M.M.,et al. The Mid-Ludfordian (late Silurian) Glaciation: A link with global changes in ocean chemistry and ecosystem overturns[J],2021,220.
APA	Frýda J..,Lehnert O..,Joachimski M.M..,Männik P..,Kubajko M..,...&Frýdová B..(2021).The Mid-Ludfordian (late Silurian) Glaciation: A link with global changes in ocean chemistry and ecosystem overturns.Earth Science Reviews,220.
MLA	Frýda J.,et al."The Mid-Ludfordian (late Silurian) Glaciation: A link with global changes in ocean chemistry and ecosystem overturns".Earth Science Reviews 220(2021).