HR: 14:40h
AN: GP33E-05    [Abstracts]
TI: Sedimentary paleointensity records by the suspension method from Pacific deep-sea sediments
AU: * Fukuma, K
EM: kfukuma@mail.doshisha.ac.jp
AF: Department of Environmental System Science, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe, 610-0394, Japan
AU: Sato, T
EM: staka@hiroshima-u.ac.jp
AF: Department of Environmental Sciences, Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8521, Japan
AB: We applied the suspension method (Yoshida and Katsura, 1985) for grayish calcareous ooze collected from the equatorial western Pacific and obtained relative paleointensity records. Although sedimentary paleointensity data have been accumulated, the acquisition processes of detrital remanence are still not fully understood and intensity normalizers such as ARM or IRM have been empirically chosen for particular sediment cores. The suspension method can give a concentration of magnetic material that is free from interaction effects and called complete alignment magnetization (CAM), and the distribution of grain size is also obtained. The estimated grain size is about 70 nm, which is of the single-domain magnetite and consistent to the TEM observation. The normalized NRM intensities by CAM show quite similar patterns with those normalized by ARM and IRM, and concordant with other coeval records from the western Pacific. The suspension method can be served as a reliable and promising approach in sedimentary paleointensity studies.
DE: 1521 Paleointensity
DE: 1540 Rock and mineral magnetism
DE: 1594 Instruments and techniques
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting