High pressure magnetic transition in pyrrhotite and impact demagnetization on Mars
AffiliationUniv Arizona, Lunar and Planetary Lab
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationHigh pressure magnetic transition in pyrrhotite and impact demagnetization on Mars 2003, 30 (13) Geophysical Research Letters
JournalGeophysical Research Letters
RightsCopyright 2003 by the American Geophysical Union.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractUsing neutron diffraction under pressure at room temperature, we observed that pyrrhotite undergoes a ferrimagnetic to paramagnetic transition at about 2.8 GPa. Complete demagnetization of remanence at the same pressure is confirmed in an independent experiment. Such a process provides a quantitative explanation of the magnetic structure of the Martian Southern Hemisphere assuming that pyrrhotite is the major magnetic mineral and that our static experiments can be extrapolated to dynamic pressure conditions. Indeed, the 3 GPa isobaric line during the two large impacts of Argyre and Hellas separates the magnetized and unmagnetized zones. We also infer a reinterpretation of Martian meteorites paleomagnetic signal.
Note6 month embargo; First published: 5 July 2003
VersionFinal published version
SponsorsProject supported by the PNP program from CNES and CNRS.