气候变化领域集成服务门户(CCPortal): Magmatic thickening of crust in non-plate tectonic settings initiated the subaerial rise of Earth's first continents 3.3 to 3.2 billion years ago

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DOI	10.1073/pnas.2105746118
	Magmatic thickening of crust in non-plate tectonic settings initiated the subaerial rise of Earth's first continents 3.3 to 3.2 billion years ago
	Chowdhury P.; Mulder J.A.; Cawood P.A.; Bhattacharjee S.; Roy S.; Wainwright A.N.; Nebel O.; Mukherjee S.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:46
英文摘要	When and how Earth's earliest continents-the cratons-first emerged above the oceans (i.e., emersion) remain uncertain. Here, we analyze a craton-wide record of Paleo-to-Mesoarchean granitoid magmatism and terrestrial to shallow-marine sedimentation preserved in the Singhbhum Craton (India) and combine the results with isostatic modeling to examine the timing and mechanism of one of the earliest episodes of large-scale continental emersion on Earth. Detrital zircon U-Pb(-Hf) data constrain the timing of terrestrial to shallow-marine sedimentation on the Singhbhum Craton, which resolves the timing of craton-wide emersion. Time-integrated petrogenetic modeling of the granitoids quantifies the progressive changes in the cratonic crustal thickness and composition and the pressure-temperature conditions of granitoid magmatism, which elucidates the underlying mechanism and tectonic setting of emersion. The results show that the entire Singhbhum Craton became subaerial ∼3.3 to 3.2 billion years ago (Ga) due to progressive crustal maturation and thickening driven by voluminous granitoid magmatism within a plateau-like setting. A similar sedimentary-magmatic evolution also accompanied the early (>3 Ga) emersion of other cratons (e.g., Kaapvaal Craton). Therefore, we propose that the emersion of Earth's earliest continents began during the late Paleoarchean to early Mesoarchean and was driven by the isostatic rise of their magmatically thickened (∼50 km thick), buoyant, silica-rich crust. The inferred plateau-like tectonic settings suggest that subduction collision-driven compressional orogenesis was not essential in driving continental emersion, at least before the Neoarchean. We further surmise that this early emersion of cratons could be responsible for the transient and localized episodes of atmospheric-oceanic oxygenation (O2-whiffs) and glaciation on Archean Earth. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Archean geodynamics; Continental emersion; Crustal thickness; Emite-granodiorite; O2 whiffs and glaciation; Tonalite-trondh
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238597
作者单位	School of Earth, Atmosphere and Environment, Monash University, Clayton, VIC 3800, Australia; School of Earth and Environmental Sciences, University of Queensland, St Lucia, QLD 4067, Australia; Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; School of Geography., Earth and Atmospheric Sciences, The University of Melbourne, Melbourne, VIC 3010, Australia; Department of Geology, University of Delhi, Delhi, 110007, India
推荐引用方式 GB/T 7714	Chowdhury P.,Mulder J.A.,Cawood P.A.,et al. Magmatic thickening of crust in non-plate tectonic settings initiated the subaerial rise of Earth's first continents 3.3 to 3.2 billion years ago[J],2021,118(46).
APA	Chowdhury P..,Mulder J.A..,Cawood P.A..,Bhattacharjee S..,Roy S..,...&Mukherjee S..(2021).Magmatic thickening of crust in non-plate tectonic settings initiated the subaerial rise of Earth's first continents 3.3 to 3.2 billion years ago.Proceedings of the National Academy of Sciences of the United States of America,118(46).
MLA	Chowdhury P.,et al."Magmatic thickening of crust in non-plate tectonic settings initiated the subaerial rise of Earth's first continents 3.3 to 3.2 billion years ago".Proceedings of the National Academy of Sciences of the United States of America 118.46(2021).