气候变化领域集成服务门户(CCPortal): Earth’s earliest granitoids are crystal-rich magma reservoirs tapped by silicic eruptions

CCPortal

DOI	10.1038/s41561-019-0520-6
	Earth’s earliest granitoids are crystal-rich magma reservoirs tapped by silicic eruptions
	Laurent O.; Björnsen J.; Wotzlaw J.-F.; Bretscher S.; Pimenta Silva M.; Moyen J.-F.; Ulmer P.; Bachmann O.
发表日期	2020
ISSN	17520894
卷号	13 期号:2
英文摘要	Granitoids of the tonalite–trondhjemite–granodiorite (TTG) series dominate Earth’s earliest continental crust. The geochemical diversity of TTGs is ascribed to several possible geodynamic settings of magma formation, from low-pressure differentiation of oceanic plateaus to high-pressure melting of mafic crust at convergent plate margins. These interpretations implicitly assume that the bulk-rock compositions of TTGs did not change from magma generation in the source to complete crystallization. However, crystal–liquid segregation influences the geochemistry of felsic magmas, as shown by the textural and chemical complementarity between coeval plutons and silicic volcanic rocks in the Phanerozoic Eon. We demonstrate here that Paleoarchean (ca. 3,456 million years old) TTG plutons from South Africa do not represent liquids but fossil, crystal-rich magma reservoirs left behind by the eruption of silicic volcanic rocks, being possibly coeval at the million-year scale as constrained by high-precision uranium–lead geochronology. The chemical signature of the dominant trondhjemites, conventionally interpreted as melts generated by high-pressure melting of basalts, reflects the combined accumulation of plagioclase phenocrysts and loss of interstitial liquid that erupted as silicic volcanic rocks. Our results indicate that the entire compositional diversity of TTGs could derive from the upper crustal differentiation of a single, tonalitic magma formed by basalt melting and/or crystallization at <40 km depth. These results call for a unifying model of Hadean–Archean continent nucleation by intracrustal production of TTG magmas. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	complementarity; crystallization; geochemistry; granitoid; magma chamber; Phanerozoic; plagioclase; volcanic rock; South Africa
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/124513
作者单位	ETH Zürich, Department of Earth Sciences, Institute for Geochemistry and Petrology, Zürich, Switzerland; Université de Lyon, Université Jean Monnet, Laboratoire Magmas et Volcans (UMR6524-CNRS-IRD), Saint-Étienne, France
推荐引用方式 GB/T 7714	Laurent O.,Björnsen J.,Wotzlaw J.-F.,等. Earth’s earliest granitoids are crystal-rich magma reservoirs tapped by silicic eruptions[J],2020,13(2).
APA	Laurent O..,Björnsen J..,Wotzlaw J.-F..,Bretscher S..,Pimenta Silva M..,...&Bachmann O..(2020).Earth’s earliest granitoids are crystal-rich magma reservoirs tapped by silicic eruptions.Nature Geoscience,13(2).
MLA	Laurent O.,et al."Earth’s earliest granitoids are crystal-rich magma reservoirs tapped by silicic eruptions".Nature Geoscience 13.2(2020).