气候变化领域集成服务门户(CCPortal): Convective isolation of hadean mantle reservoirs through archean time

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DOI	10.1073/pnas.2012626118
	Convective isolation of hadean mantle reservoirs through archean time
	Tusch J.; Münker C.; Hasenstab E.; Jansen M.; Marien C.S.; Kurzweil F.; van Kranendonk M.J.; Smithies H.; Maier W.; Garbe-Schönberg D.
发表日期	2021
ISSN	00278424
卷号	118 期号:2
英文摘要	Although Earth has a convecting mantle, ancient mantle reservoirs that formed within the first 100 Ma of Earth’s history (Hadean Eon) appear to have been preserved through geologic time. Evidence for this is based on small anomalies of isotopes such as 182W, 142Nd, and 129Xe that are decay products of short-lived nuclide systems. Studies of such short-lived isotopes have typically focused on geological units with a limited age range and therefore only provide snapshots of regional mantle heterogeneities. Here we present a dataset for short-lived 182Hf−182W (half-life 9 Ma) in a comprehensive rock suite from the Pilbara Craton, Western Australia. The samples analyzed preserve a unique geological archive covering 800 Ma of Archean history. Pristine 182W signatures that directly reflect the W isotopic composition of parental sources are only preserved in unaltered mafic samples with near canonical W/Th (0.07 to 0.26). Early Paleoarchean, mafic igneous rocks from the East Pilbara Terrane display a uniform pristine μ182W excess of 12.6 ± 1.4 ppm. From ca. 3.3Ga onward, the pristine 182W signatures progressively vanish and are only preserved in younger rocks of the craton that tap stabilized ancient lithosphere. Given that the anomalous 182W signature must have formed by ca. 4.5 Ga, the mantle domain that was tapped by magmatism in the Pilbara Craton must have been convectively isolated for nearly 1.2 Ga. This finding puts lower bounds on timescale estimates for localized convective homogenization in early Earth’s interior and on the widespread emergence of plate tectonics that are both important input parameters in many physical models. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Early earth; Late veneer; Mantle convection; Pilbara craton; Tungsten isotopes
语种	英语
scopus关键词	neodymium 142; radioisotope; tungsten 182; unclassified drug; w 182; xenon 129; ancient mantle reservoir; Archean; Article; chemical composition; geographic and geological parameters; Hadean; half life time; igenous rock; lithosphere; priority journal; radiometric dating; rock; time; Western Australia
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/181090
作者单位	Institut für Geologie und Mineralogie, Universität zu Köln, Köln, 50674, Germany; School of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, NSW 2052, Australia; Australian Center for Astrobiology, The University of New South Wales, Kensington, NSW 2052, Australia; Department of Mines, Industry Regulations and Safety, Geological Survey of Western Australia, East Perth, WA 6004, Australia; School of Earth and Ocean Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom; Institut für Geowissenschaften, Universität zu Kiel, Kiel, 24118, Germany
推荐引用方式 GB/T 7714	Tusch J.,Münker C.,Hasenstab E.,et al. Convective isolation of hadean mantle reservoirs through archean time[J],2021,118(2).
APA	Tusch J..,Münker C..,Hasenstab E..,Jansen M..,Marien C.S..,...&Garbe-Schönberg D..(2021).Convective isolation of hadean mantle reservoirs through archean time.Proceedings of the National Academy of Sciences of the United States of America,118(2).
MLA	Tusch J.,et al."Convective isolation of hadean mantle reservoirs through archean time".Proceedings of the National Academy of Sciences of the United States of America 118.2(2021).