Abstract
Investigating mineral magnetic properties of meteorites is essential to understanding the formation and evolution of planetary bodies in the solar system. In order to decipher ancient magnetic records, demagnetization experiments were carried out for the ∼4550 Ma Richardton H5 chondrite. Alternating-field demagnetization revealed a soft fraction as well as a hard fraction. Conventional thermal demagnetization in air showed severe alterations. But, a few thermal demagnetizations in vacuum were successful in isolating a stable paleomagnetic record. On the basis of microscopic analysis, we found that fine-grained clinopyroxene-hosted kamacite is abundant, responsible for the stable and permanent magnetic record of Richardton. The experimental data imply a thermal or thermochemical origin for the stable paleomagnetic record of Richardton. However, the possibility of pressure (re)magnetization cannot be evaluated because the effect of pressure on magnetization for the Fe-Ni system is unknown.
Original language | English |
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Pages (from-to) | 12-18 |
Number of pages | 7 |
Journal | Physics of the Earth and Planetary Interiors |
Volume | 177 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2009 Nov |
Bibliographical note
Funding Information:This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded to S.J.D. by the Korea government (MOST) (No. R01-2007-000-10517-0). Mike Jackson of the Institute for Rock Magnetism (IRM) provided invaluable help with the low-temperature measurements. The Keck Foundation, the National Science Foundation, Earth Sciences Division, and the University of Minnesota provide funding for the IRM. Jérôme Gattacceca and Gunther Kletetschka shared fruitful suggestions on an earlier draft of the manuscript. Rodney H. Grapes kindly corrected the English of this manuscript. The manuscript was greatly improved by careful and constructive reviews of an anonymous referee and editor Keke Zhang.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
Keywords
- Chondrite
- Fe-Ni system
- Kamacite
- Meteorite
- Richardton
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Geophysics
- Physics and Astronomy (miscellaneous)
- Space and Planetary Science