image: The internal zoning of Jack Hills zircon, recording its formation nearly 4 billion years ago. view more
Credit: Image courtesy of Richard J. M. Taylor.
Although zircon crystals from Jack Hills, Australia are some of the oldest minerals on Earth, dating to the early Hadean Eon, researchers report that magnetite within the zircons, which could preserve a record of Earth's earliest magnetic field, is most likely a secondary deposit, formed long after the zircons crystallized; the results suggest that without evidence of primary magnetite, the existence of a magnetic field in the Hadean Eon remains unknown.
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Article #18-11074: "Secondary magnetite in ancient zircon precludes analysis of a Hadean geodynamo," by Fengzai Tang et al.
MEDIA CONTACT: Rich J. M. Taylor, University of Cambridge, UNITED KINGDOM; e-mail: <rjt79@cam.ac.uk>
Journal
Proceedings of the National Academy of Sciences