DOI: 10.1016/j.epsl.2018.04.047
Scopus记录号: 2-s2.0-85046804191
论文题名: Petrogenesis and tectonics of the Acasta Gneiss Complex derived from integrated petrology and 142Nd and 182W extinct nuclide-geochemistry
作者: Reimink J.R. ; Chacko T. ; Carlson R.W. ; Shirey S.B. ; Liu J. ; Stern R.A. ; Bauer A.M. ; Pearson D.G. ; Heaman L.M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 494 起始页码: 12
结束页码: 22
语种: 英语
英文关键词: 142Nd
; 182W
; Acasta Gneiss Complex
; early Earth
; triple oxygen isotopes
Scopus关键词: Garnets
; Geochemistry
; Hydration
; Isotopes
; Melting
; Oxygen
; Petrology
; Silicate minerals
; Zircon
; Zircon deposits
; Early Earth
; Gneiss complexes
; Triple oxygen isotopes
; ^142Nd
; ^182W
; Igneous rocks
; Acasta
英文摘要: The timing and mechanisms of continental crust formation represent major outstanding questions in the Earth sciences. Extinct-nuclide radioactive systems offer the potential to evaluate the temporal relations of a variety of differentiation processes on the early Earth, including crust formation. Here, we investigate the whole-rock 182W/184W and 142Nd/144Nd ratios and zircon Δ17O values of a suite of well-studied and lithologically-homogeneous meta-igneous rocks from the Acasta Gneiss Complex, Northwest Territories, Canada, including the oldest-known zircon-bearing rocks on Earth. In the context of previously published geochemical data and petrogenetic models, the new 142Nd/144Nd data indicate that formation of the Hadean–Eoarchean Acasta crust was ultimately derived from variable sources, both in age and composition. Although 4.02 Ga crust was extracted from a nearly bulk-Earth source, heterogeneous μ 142Nd signatures indicate that Eoarchean rocks of the Acasta Gneiss Complex were formed by partial melting of hydrated, Hadean-age mafic crust at depths shallower than the garnet stability field. By ∼3.6 Ga, granodioritic–granitic rocks were formed by partial melting of Archean hydrated mafic crust that was melted at greater depth, well into the garnet stability field. Our 182W results indicate that the sources to the Acasta Gneiss Complex had homogeneous, high-μ182W on the order of +10 ppm—a signature ubiquitous in other Eoarchean terranes. No significant deviation from the terrestrial mass fractionation line was found in the triple oxygen isotope (16O–17O–18O) compositions of Acasta zircons, confirming homogeneous oxygen isotope compositions in Earth's mantle by 4.02 Ga. © 2018 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109859
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015, United States; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G2E3, Canada; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, China; Department of Geology and Geophysics, Yale University, New Haven, CT 06511, United States
Recommended Citation:
Reimink J.R.,Chacko T.,Carlson R.W.,et al. Petrogenesis and tectonics of the Acasta Gneiss Complex derived from integrated petrology and 142Nd and 182W extinct nuclide-geochemistry[J]. Earth and Planetary Science Letters,2018-01-01,494