Open AccessDecay of a post‐depositional remanent magnetization in wet sediments due to the effect of drying
Author(s) -
Otofuji Yoichiro,
Katsura Ikuo,
Sasajima Sadao
Publication year - 1982
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1982.tb06399.x
Subject(s) - remanence , magnetization , evaporation , geology , natural remanent magnetization , sedimentary depositional environment , rock magnetism , condensed matter physics , magnetic field , physics , geomorphology , thermodynamics , structural basin , quantum mechanics
Summary. The decay of the post‐depositional remanent magnetization (post‐DRM) during desiccation in magnetic field free space is measured as a function of the loss of water. The decay is ascribed to the drying effect and the time decay of viscous remanent magnetization (VRM). The VRM forms only 10 per cent of the total of loss of remanent magnetization. The decay due to the drying effects depends both on the loss of water and on either the evaporation rate or the period of storage. The percentage of loss of magnetization is independent of its intensity. A critical drying stage appears (about 60 per cent in water content on a dry basis) which is characterized as a vanishing point of mobile particles or particle units. The mobile particles or units play an important role both in acquisition and demagnetization through physical rotational motion within wet sediments before the critical drying stage. More than 80 per cent of the total loss of the post‐DRM is destroyed before the desiccation proceeds to the critical drying stage. The decay of post‐DRh4 is concluded to be mainly due to the physically random rotation of the magnetic particles trapped in shallow energy wells which are overcome by the torques caused by the application of the alternating magnetic field less than 200 Oe.