2019 Volume 56 Issue 5 Pages 264-272
Slip direction is key for understanding the propagation direction of large-scale landslides. Although the slip directions of shear zones are commonly measured using striations on the slip surface and/or internal particle arrangements, it is still hard to decipher the slip direction from a landslide. In this paper, we demonstrate a quick method to measure slip direction using rock magnetic measurements of samples provided by a ring shear test.
Using anisotropy of magnetic susceptibility (AMS), we measured five specimens taken from the sample before the shear test and found that the maximum axes of the AMS ellipsoid (kmax) for all specimens were parallel. However, in the six specimens taken from the sample after the shear test, the kmax was oriented in tangent to the circular sample－an obvious change compared to the results before the shearing. When studying the remanent magnetization, the declination of many specimens after the shear test were found to be oriented in a near-tangential direction ; we obtained the same result using AMS. These results suggest that the magnetic particles of the specimen after the ring shear test are arranged in a circumferential direction. This study showed that the direction of slip motion could be reproduced from the rock magnetic properties of the slip surface.
