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DOI	10.1016/j.epsl.2020.116730
	Stirred not shaken; critical evaluation of a proposed Archean meteorite impact in West Greenland
	Yakymchuk C.; Kirkland C.L.; Cavosie A.J.; Szilas K.; Hollis J.; Gardiner N.J.; Waterton P.; Steenfelt A.; Martin L.
发表日期	2021
ISSN	0012821X
卷号	557
英文摘要	Large meteorite impacts have a profound effect on the Earth's geosphere, atmosphere, hydrosphere and biosphere. It is widely accepted that the early Earth was subject to intense bombardment from 4.5 to 3.8 Ga, yet evidence for subsequent bolide impacts during the Archean Eon (4.0 to 2.5 Ga) is sparse. However, understanding the timing and magnitude of these early events is important, as they may have triggered significant change points to global geochemical cycles. The Maniitsoq region of southern West Greenland has been proposed to record a ∼3.0 Ga meteorite impact, which, if confirmed, would be the oldest and only known impact structure to have survived from the Archean. Such an ancient structure would provide the first insight into the style, setting, and possible environmental effects of impact bombardment continuing into the late Archean. Here, using field mapping, geochronology, isotope geochemistry, and electron backscatter diffraction mapping of 5,587 zircon grains from the Maniitsoq region (rock and fluvial sediment samples), we test the hypothesis that the Maniitsoq structure represents Earth's earliest known impact structure. Our comprehensive survey shows that previously proposed impact-related geological features, ranging from microscopic structures at the mineral scale to macroscopic structures at the terrane scale, as well as the age and geochemistry of the rocks in the Maniitsoq region, can be explained through endogenic (non-impact) processes. Despite the higher impact flux, intact craters from the Archean Eon remain elusive on Earth. © 2020 The Author(s)
关键词	bolide impact Maniitsoq North Atlantic Craton planar deformation features zircon
英文关键词	Earth atmosphere; Exploratory geochemistry; Geochronology; Mapping; Meteorites; Silicate minerals; Structural geology; Zircon; Critical evaluation; Electron back scatter diffraction; Geological features; Global geochemical cycles; Isotope geochemistry; Macroscopic structure; Microscopic structures; Southern west greenland; Meteor impacts; Archean; bolide; deformation; environmental effect; meteorite; terrane; zircon; Arctic; Greenland; North Atlantic Craton; West Greenland
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203345
作者单位	Department of Earth and Environmental Sciences, University of Waterloo, Canada; Timescales of Mineral Systems Group, Centre for Exploration Targeting - Curtin Node, School of Earth and Planetary Sciences, Curtin University, Perth, Australia; Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Australia; Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, Copenhagen K, 1350, Denmark; Department of Geology, Ministry of Mineral Resources, Government of Greenland, P.O. Box 930, Nuuk, 3900, Greenland; School of Earth and Environmental Sciences, University of St Andrews, St Andrews, KY16 9AL, United Kingdom; The Geological Survey of Denmark and Greenland, Øster Voldgade 10, Copenhagen K, 1350, Denmark; Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
推荐引用方式 GB/T 7714	Yakymchuk C.,Kirkland C.L.,Cavosie A.J.,et al. Stirred not shaken; critical evaluation of a proposed Archean meteorite impact in West Greenland[J],2021,557.
APA	Yakymchuk C..,Kirkland C.L..,Cavosie A.J..,Szilas K..,Hollis J..,...&Martin L..(2021).Stirred not shaken; critical evaluation of a proposed Archean meteorite impact in West Greenland.Earth and Planetary Science Letters,557.
MLA	Yakymchuk C.,et al."Stirred not shaken; critical evaluation of a proposed Archean meteorite impact in West Greenland".Earth and Planetary Science Letters 557(2021).