气候变化领域集成服务门户(CCPortal): Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa

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DOI	10.1016/j.epsl.2021.116999
	Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa
	Fu R.R.; Drabon N.; Wiedenbeck M.; Brenner A.R.; Lowe D.R.; Borlina C.S.
发表日期	2021
ISSN	0012821X
卷号	567
英文摘要	The existence of a core dynamo during the first billion years of Earth history is closely related to the thermal state of the Earth's interior and composition of the early atmosphere. The scarcity of well-preserved rock units older than 3.5 billion years (Ga) has motivated the paleomagnetic analysis of detrital zircons. Studies of zircons from Jack Hills, Australia, however, have found the pervasive occurrence of secondary ferromagnetic minerals, casting doubt on the ability of these zircons to record a >3.5 Ga geomagnetic field. Here we report paleomagnetic analyses on a set of 19 zircons with crystallization age 3.5-4.0 Ga from the Barberton Greenstone Belt (BGB) of South Africa, which have undergone lower grade metamorphism compared to all other known >3.5 Ga detrital zircon localities. We find that BGB zircons have magnetic moments nearly one order of magnitude weaker than Jack Hills zircons, precluding the retention of primary paleomagnetic information. This result corroborates findings from the Jack Hills and other Archean zircon populations that primary ferromagnetic inclusions are readily eliminated from zircons during sedimentary transport and metamorphism, likely facilitated by radiation damage-induced permeability. Paleomagnetic determination of geodynamo activity prior to 3.5 Ga may require investigation of other detrital grains with lower radiation damage potential or whole-rock samples that have escaped high degree metamorphism. © 2021 Elsevier B.V.
关键词	Barberton Greenstone Belt geodynamo geophysics paleomagnetism rock magnetism zircons
英文关键词	Geophysics; Radiation damage; Zircon; Barberta greenstone belt; Barberton; Detrital zircon; Geodynamo; Greenstone belts; Jack hills; Paleomagnetic analysis; Rock magnetism; South Africa; Zircon; Geomagnetism; geodynamo; geophysics; greenstone; paleomagnetism; rock property; zircon; Barberton Greenstone Belt
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203092
作者单位	Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Department of Geological Sciences, Stanford University, Stanford, CA, United States; Deutsche Geoforschungszentrum (GFZ), Potsdam, Germany; Department of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, MA, United States
推荐引用方式 GB/T 7714	Fu R.R.,Drabon N.,Wiedenbeck M.,et al. Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa[J],2021,567.
APA	Fu R.R.,Drabon N.,Wiedenbeck M.,Brenner A.R.,Lowe D.R.,&Borlina C.S..(2021).Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa.Earth and Planetary Science Letters,567.
MLA	Fu R.R.,et al."Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa".Earth and Planetary Science Letters 567(2021).