DOI: 10.1016/j.epsl.2020.116091
论文题名: North Atlantic Craton architecture revealed by kimberlite-hosted crustal zircons
作者: Gardiner N.J. ; Kirkland C.L. ; Hollis J.A. ; Cawood P.A. ; Nebel O. ; Szilas K. ; Yakymchuk C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 534 语种: 英语
中文关键词: Archean Archaean
; Greenland
; Isukasia Akia Terrane
; Itsaq Isua
; lamprophyre
; SCLM lithosphere mantle
英文关键词: Isotopes
; Silicate minerals
; Trace elements
; Zircon
; Archaean
; Greenland
; Isukasia Akia Terrane
; Itsaq Isua
; Lamprophyre
; Lithosphere mantle
; Volcanic rocks
; Archean
; crustal evolution
; hafnium
; kimberlite
; lamprophyre
; lead isotope
; lithospheric structure
; petrology
; uranium isotope
; zircon
; North Atlantic Craton
英文摘要: Archean cratons are composites of terranes formed at different times, juxtaposed during craton assembly. Cratons are underpinned by a deep lithospheric root, and models for the development of this cratonic lithosphere include both vertical and horizontal accretion. How different Archean terranes at the surface are reflected vertically within the lithosphere, which might inform on modes of formation, is poorly constrained. Kimberlites, which originate from significant depths within the upper mantle, sample cratonic interiors. The North Atlantic Craton, West Greenland, comprises Eoarchean and Mesoarchean gneiss terranes – the latter including the Akia Terrane – assembled during the late Archean. We report U–Pb and Hf isotopic, and trace element, data measured in zircon xenocrysts from a Neoproterozoic (557 Ma) kimberlite which intruded the Mesoarchean Akia Terrane. The zircon trace element profiles suggest they crystallized from evolved magmas, and their Eo- to Neoarchean U–Pb ages match the surrounding gneiss terranes, and highlight that magmatism was episodic. Zircon Hf isotope values lie within two crustal evolution trends: a Mesoarchean trend and an Eoarchean trend. The Eoarchean trend is anchored on 3.8 Ga orthogneiss, and includes 3.6–3.5 Ga, 2.7 and 2.5–2.4 Ga aged zircons. The Mesoarchean Akia Terrane may have been built upon mafic crust, in which case all zircons whose Hf isotopes lie within the Eoarchean trend were derived from the surrounding Eoarchean gneiss terranes, emplaced under the Akia Terrane after ca. 2.97 or 2.7 Ga, perhaps during late Archean terrane assembly. Kimberlite-hosted peridotite rhenium depletion model ages suggest a late Archean stabilization for the lithospheric mantle. The zircon data support a model of lithospheric growth via tectonic stacking for the North Atlantic Craton. © 2020 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164976
Appears in Collections: 气候变化与战略
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作者单位: School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, KT16 9AL, United Kingdom; School of Earth, Atmosphere and Environment, Monash University, Victoria, 3800, Australia; Centre for Exploration Targeting – Curtin Node, School of Earth and Planetary Sciences, Curtin University, Perth, Australia; Department of Geology, Ministry of Mineral Resources, Government of Greenland, P.O. Box 930, Nuuk3900, Greenland; Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, Copenhagen K, DK-1350, Denmark; Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
Recommended Citation:
Gardiner N.J.,Kirkland C.L.,Hollis J.A.,et al. North Atlantic Craton architecture revealed by kimberlite-hosted crustal zircons[J]. Earth and Planetary Science Letters,2020-01-01,534