HR: 13:40h
AN: GP22A-01    [PDF]
TI: Paleomagnetic Records of the Moon and Mars
AU: Cisowski, S
EM: scisowski@geol.ucsb.edu
AF: HIGP-SOEST, U.Hawaii, 1618 East-West rd, Honolulu, HI 96822 United States
AU: * Fuller, M
EM: mfuller@soest.hawaii.edu
AF: HIGP-SOEST, U.Hawaii, 1618 East-West rd, Honolulu, HI 96822 United States
AB: The Moon and Mars afford two examples of major evolved solar system bodies for which we have paleomagnetic records, but no evidence for a presently active dynamo. The records from the Moon and Mars include satellite, or sub-satellite magnetic survey data and the paleomagnetism of samples brought to earth as meteorites. In addition, for the moon we have the record of the Apollo samples. We interpret the lunar paleomagnetic record in terms of a strong magnetic field era from approximately 3.85 - 3.65 Ga, when the surface field was comparable with earth's field and that outside of this period the field cannot be convincingly distinguished from background noise. Mars may also have had a relatively short period of a strong dynamo field, if the interpretation of the demagnetization effects of Hellas and Argyre and the estimates of their age are correct. Evidence from ALH 84001, is consistent with a surface field about an order of magnitude smaller than the earth's field. In comparing these surface fields it is perhaps worth noting that if the efficiency of the various dynamos are similar, being for example dependent upon the linear dimension of the source region, the surface fields will necessarily be larger on smaller bodies.
DE: 1519 Magnetic mineralogy and petrology
DE: 1540 Rock and mineral magnetism
DE: 6022 Impact phenomena
DE: 6030 Magnetic fields and magnetism
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2003 Fall Meeting