Авторы: Masahiko Sato, Nobutatsu Mochizuki, Minako Watanabe, Hideo Tsunakawa

2016 г.

GGG

     The basic properties of oblique anhysteretic remanent magnetization (OARM) acquired in a weak and steady magnetic field with an arbitrary angle to the alternating field direction were studied. OARM and rock-magnetic experiments were conducted on samples of basalt, granite, and sediment containing noninteracting single domain (SD), interacting SD, pseudo-single-domain, and multidomain low-Ti titanomagnetites. The intensity of OARM (MOARM) systematically increased or decreased with increasing angle between alternating and steady field directions (hSF), while the angle between alternating field and OARM directions (hOARM) increased with increasing hSF for all samples. During stepwise alternating field demagnetization, the OARM vector shows a single component parallel to the steady field direction for hSF508 (ARMjj) and 908 (ARM?). The median destructive field of ARM? is larger than that of ARMjj. For intermediate angles (hSF5308, 458, and 608), the OARM vector did not parallel the applied steady field but gradually increased hOARM with higher coercivity. These experiments indicate that the OARM vector is approximately given by the sum of two orthogonal magnetizations coinciding with ARMjj and ARM?, respectively. Thus, the OARM vector can be determined by acquisition efficiencies of ARMjj and ARM? in an individual sample. Based on these experiments and associated rock-magnetic measurements, noninteracting SD samples show lower ARM?/ARMjj ratios, compared to other samples. This result suggests that OARM can be used as a useful tool to detect noninteracting SD particles in the paleomagnetic samples.

Файл: 1033.pdf