Hand Magnets and the Destruction of Ancient Meteorite Magnetism
Name
JGR Planets - 2023 - Vervelidou - Hand Magnets and the Destruction of Ancient Meteorite Magnetism.pdf
Description
Published version
Size
3.24 MB
Format
Adobe PDF
Checksum (MD5)
3a97a271794be28fc9f92c0432727938
Author(s)
Vervelidou, Foteini
Weiss, Benjamin P
Lagroix, France
Date Issued
April 6, 2023
Journal
Journal of Geophysical Research: Planets
Publisher
American Geophysical Union
Citation
Vervelidou, F., Weiss, B. P., & Lagroix, F.
(2023). Hand magnets and the destruction
of ancient meteorite magnetism. Journal
of Geophysical Research: Planets,
128, e2022JE007464.
Version
Final published version
Abstract
Meteorites provide invaluable records of planetary formation and evolution. Studies of their paleomagnetism have constrained accretion in the protoplanetary disk, the thermal evolution and differentiation of planetesimals, and the history of planetary dynamos. Yet, the potential of these magnetic records in advancing the field of planetary science is severely hindered by a widely used technique: application of hand magnets to assist in meteorite classification. Touching a meteorite with a magnet results in near‐instantaneous destruction of its magnetic record. Here, we showcase the destructive effects of exposing meteorites to magnets through numerical modeling, a controlled remagnetization experiment on a terrestrial basalt, and a paleomagnetic study of the oldest known Martian meteorite, the Northwest Africa (NWA) 7034 pairing group. NWA 7034 is a polymict regolith breccia containing zircon crystals with crystallization ages older than 4.4 billion years. As such it contains materials that are sufficiently old to have formed during the time Mars is most likely to have had a core dynamo. Unfortunately, we found that all nine paired stones of NWA 7034 that we investigated were remagnetized by hand magnets, as has been observed for many other hot desert meteorites. We recommend that magnets not be applied to meteorites during collection and curation. Instead, a low‐field susceptibility meter is a far more sensitive and completely nondestructive tool for meteorite classification.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
10.1029/2022je007464
