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DOI	10.1038/s41561-019-0407-6
	An oceanic subduction origin for Archaean granitoids revealed by silicon isotopes
	Deng Z.; Chaussidon M.; Guitreau M.; Puchtel I.S.; Dauphas N.; Moynier F.
发表日期	2019
ISSN	17520894
卷号	12 期号:9
英文摘要	Modern oceanic crust is constantly produced at oceanic ridges and recycled back into the mantle at subduction zones via plate tectonics. An outstanding question in geology is whether the Earth started in a non-plate tectonic regime, and if it did, when the transition to the modern regime occurred. This is a complicated question to address because Archaean rocks lack modern equivalents to anchor interpretations. Here, we present a silicon isotopic study of 4.0–2.8-Gyr-old tonalite–trondhjemite–granodiorites, as well as Palaeozoic granites and modern adakites. We show that Archaean granitoids have heavier silicon isotopic compositions than granites and adakites, regardless of melting pressure. This is best explained if Archaean granitoids were formed by melting of subducted basaltic crust enriched in sedimentary silica through interaction with seawater. Before the appearance of silica-forming organisms 0.5–0.6 billion years ago, the oceans were close to silicon saturation, which led to extensive precipitation of cherts on the seafloor. This is in contrast to modern oceans, where silica biomineralization maintains dissolved silicon at low concentration. The unique heavy silicon isotope signature of cherts has been transferred to Archaean granitoids during an oceanic subduction process, which was probably responsible for the formation of felsic rocks on Archaean emerged lands. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	adakite; biomineralization; granitoid; isotopic composition; melting; mid-ocean ridge; oceanic crust; plate tectonics; seafloor; silicon; subduction; tonalite; trondhjemite
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/124603
作者单位	Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France; Université Clermont Auvergne, Laboratoire Magmas et Volcans, IRD, CNRS, UMR 6524, Aubière, France; Department of Geology, University of Maryland, College Park, MD, United States; Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, Chicago, IL, United States; Institut Universitaire de France, Paris, France
推荐引用方式 GB/T 7714	Deng Z.,Chaussidon M.,Guitreau M.,et al. An oceanic subduction origin for Archaean granitoids revealed by silicon isotopes[J],2019,12(9).
APA	Deng Z.,Chaussidon M.,Guitreau M.,Puchtel I.S.,Dauphas N.,&Moynier F..(2019).An oceanic subduction origin for Archaean granitoids revealed by silicon isotopes.Nature Geoscience,12(9).
MLA	Deng Z.,et al."An oceanic subduction origin for Archaean granitoids revealed by silicon isotopes".Nature Geoscience 12.9(2019).