Characteristic of magnetic susceptibility anisotropy in and around Laji Shan and its geological significance

This paper deals with the anisotropy of magnetic susceptibility (AMS) of Laji Shan and its adjacent areas. Cenozoic sediment is a suite of mudstone and sandstone, which underwent weak deformation and no metamorphism. Most of the magnetic ellipsoids are oblate withK _max trending NW-SE, and the minimum axesK _min show a large deviation from the poles of bedding planes with an NE preferred direction. Taken together, they reflect that the magnetic fabric is mainly of tectonic origin. In the study area, the NE-SW orientation ofK _min represents the recent principal compression direction. This point is substantiated by the structures in sites where magnetic fabric data are also available. The stress field provides a strong support for the sustained uplift of Laji Shan and its adjacent areas in the late Tertiary-Quaternary period.