Reevaluating the evidence for a Hadean-Eoarchean dynamo

TitleReevaluating the evidence for a Hadean-Eoarchean dynamo
Publication TypeJournal Article
Year of Publication2020
AuthorsBorlina CS, Weiss BP, Lima EA, Tang F, Taylor RJM, Einsle JF, Harrison RJ, Fu RR, Bell EA, Alexander EW, Kirkpatrick HM, Wielicki MM, Harrison TM, Ramezani J, Maloof AC
JournalScience Advances
Volume6
Issue15
Pagination1-9
Date Published04/2020
ISSNISSN 2375-2548
Other Numbers67Maloof
Abstract

The time of origin of the geodynamo has important implications for the thermal evolution of the planetary interior and the habitability of early Earth. It has been proposed that detrital zircon grains from Jack Hills, Western Australia, provide evidence for an active geodynamo as early as 4.2 billion years (Ga) ago. However, our combined paleomagnetic, geochemical, and mineralogical studies on Jack Hills zircons indicate that most have poor magnetic recording properties and secondary magnetization carriers that postdate the formation of the zircons. Therefore, the existence of the geodynamo before 3.5 Ga ago remains unknown.

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URLhttps://doi.org/10.1126/sciadv.aav9634
DOI10.1126/sciadv.aav963