TY - JOUR
T1 - Paleomagnetic record of Martian meteorite ALH84001
AU - Antretter, Maria
AU - Fuller, Mike
AU - Scott, Edward
AU - Jackson, Mike
AU - Moskowitz, Bruce
AU - Solheid, Peter
PY - 2003/6/25
Y1 - 2003/6/25
N2 - The natural remanent magnetization (NRM) of the Martian meteorite ALH84001 is predominantly carried by fine magnetite, which is found in association with carbonate. The magnetite is in epitaxial and topotactic relation with the carbonate and formed from the carbonate in the major impact event at 4.0 Ga. The NRM will therefore record this field. The local preferential crystallographic and shape alignment of the magnetite defines local easy directions of magnetization may account for the observed inhomogeneity of the NRM on a microscopic scale. Normalizing the intensity of the NRM by the saturation isothermal remanence (IRMs) then gives an estimate for the 4.0 Ga Martian field one order smaller than the present geomagnetic field. Such a field is unlikely to be strong enough to generate the high-intensity Martian magnetic anomalies. ALH 84001 in its pristine state as an orthopyroxenite is not a plausible source rock for the Martian anomalies because its magnetite was not formed until the 4.0 Ga event.
AB - The natural remanent magnetization (NRM) of the Martian meteorite ALH84001 is predominantly carried by fine magnetite, which is found in association with carbonate. The magnetite is in epitaxial and topotactic relation with the carbonate and formed from the carbonate in the major impact event at 4.0 Ga. The NRM will therefore record this field. The local preferential crystallographic and shape alignment of the magnetite defines local easy directions of magnetization may account for the observed inhomogeneity of the NRM on a microscopic scale. Normalizing the intensity of the NRM by the saturation isothermal remanence (IRMs) then gives an estimate for the 4.0 Ga Martian field one order smaller than the present geomagnetic field. Such a field is unlikely to be strong enough to generate the high-intensity Martian magnetic anomalies. ALH 84001 in its pristine state as an orthopyroxenite is not a plausible source rock for the Martian anomalies because its magnetite was not formed until the 4.0 Ga event.
KW - ALH84001
KW - Extraterrestrial paleomagnetism
KW - Martian magnetic fields
KW - Martian meteorites
KW - Martian paleomagnetism
KW - Origin of magnetite in ALH84001
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U2 - 10.1029/2002je001979
DO - 10.1029/2002je001979
M3 - Article
AN - SCOPUS:0141676025
VL - 108
SP - 3-1 - 3-7
JO - Journal of Geophysical Research E: Planets
JF - Journal of Geophysical Research E: Planets
SN - 2169-9097
IS - 6
ER -