Magnetic anisotropy and porosity of Antarctic chondrites

• Main Authors: Yozo Hamano, Kiyoshi Yomogida
• Format: Report
• Language: English
• Published: Geophysical Institute, University of Tokyo 1982
• Subjects: Antarctic; Antarc*; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1396; http://id.nii.ac.jp/1291/00001396/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1396&item_no=1&attribute_id=18&file_no=1

Magnetic susceptibility anisotropy and porosity were measured in eleven Antarctic meteorites. These meteorites are ordinary chondrites (H and L type) in various metamorphic stages. Large magnetic anisotropy has been observed in most of the chondrites. The foliation type of the anisotropy, inferred from the shape of the susceptibility ellipsoid indicates that a uniaxial compressional type deformation is responsible for the anisotropy. The degree of the anisotropy and the porosity do not correlate with the petrologic type of the chondrites. Based on the present observation, dynamical compression during the initial accumulation stage of chondritic parent bodies was concluded as a main cause of the anisotropy. Porosity-anisotropy relation in these chondrites suggests that this accumulation stage also determined the observed porosity values.