DOI: 10.1038/ngeo1911
论文题名: Hadean mantle melting recorded by southwest Greenland chromitite 186 Os signatures
作者: Coggon J.A. ; Luguet A. ; Nowell G.M. ; Appel P.W.U.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 10 起始页码: 871
结束页码: 874
语种: 英语
Scopus关键词: chromitite
; crustal evolution
; enrichment
; Hadean
; mantle process
; osmium isotope
; partial melting
; ultramafic rock
; Arctic
; Greenland
英文摘要: Partial melting of the Earth's mantle is a key process in the generation of crustal material and the formation of continents. Crustal samples record the generation of crust up to 4.4 billion years (Gyr) ago, yet the complementary record in the mantle extends to only 3.3 Gyr ago, with sparse evidence for differentiation occurring 3.9-4.1 Gyr ago. Here we use the Pt-Os isotope chronometer to show that a Hadean record of mantle depletion is preserved in Earth's oldest known ultramafic rocks, the Ujaragssuit Nunât intrusion of southwest Greenland. We identify two distinct age populations at approximately 4.1 and 2.9 Gyr. We suggest that the younger age population records a regional metamorphic event and the older one records mantle depletion. We also identify individual sample ages of up to 4.36 Gyr old, thus extending the record of large mantle-melting events into the Hadean. Furthermore, the preservation of Hadean model ages in Os-rich mantle-derived rocks supports the theory that re-enrichment of Os in the mantle during the Late Heavy Bombardment - after expected partitioning into the Earth's core - occurred at least 0.2 Gyr earlier than previously thought. This also implies that the Earth could have been habitable by 4.1 Gyr ago. © 2013 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106691
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Steinmann Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany; Northern Centre for Isotopic and Elemental Tracing, Department of Earth Sciences, University of Durham, South Road, Durham DH1 3LE, United Kingdom; Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
Recommended Citation:
Coggon J.A.,Luguet A.,Nowell G.M.,et al. Hadean mantle melting recorded by southwest Greenland chromitite 186 Os signatures[J]. Nature Geoscience,2013-01-01,6(10)