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. ...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 with K_max trending NW-SE, and the minimum axes K_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 of K_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.展开更多
基金the National (Grant No. G1998040800) and CAS's Key Project forBasic Research on Tibetan Plateau (Grant Nos. KZ951-A1-204 and KZ95T-06), and the National Natural Science Foundation of China (Grant No. 49902019).
文摘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 with K_max trending NW-SE, and the minimum axes K_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 of K_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.
