Magnetic anisotropy indications of deformations associated with diagenesis
Magnetic anisotropy indications of deformations associated with diagenesis
复制标题
与成岩作用相关的变形的磁各向异性指示
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
J. Jezek
中科院分区：
文献类型：
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作者：
F. Hrouda;J. Jezek
摘要磁化率各向异性敏感地反映了与成岩作用和早期构造作用有关的初始韧性变形。由于上覆岩层的重力作用，垂直方向缩短的岩石中，AMS的程度增加，磁组构变得更扁。磁面理与层理平行，磁线理与水流方向接近。在岩石横向缩短，通常是由构造力，AMS和磁组构扁率的程度最初减少，只有后来增加。磁线理偏离水流方向，磁叶理偏离层理方向，磁极形成环带。AMS的变化是由于磁性颗粒的物理旋转，这对古地磁学有严重的影响，但从成岩到构造控制制度的变化的主要指标。
Abstract Anisotropy of magnetic susceptibility (AMS), as revealed by mathematical modelling and empirical studies, sensitively reflects initial ductile deformation associated with diagenesis and early tectonism. In rocks shortened vertically because of the gravitational loading by the weight of overlying strata, the degree of AMS increases and the magnetic fabric becomes more oblate. The magnetic foliation remains parallel to the bedding and the magnetic lineation remains near the water current directions. In rocks shortened laterally, usually by tectonic forces, the degree of AMS and the magnetic fabric oblateness initially decrease and only later increase. The magnetic lineation deflects from the water current direction and the magnetic foliation from the bedding, with its poles creating a girdle pattern. The AMS changes are due to the physical rotation of magnetic grains, which has serious implications for palaeomagnetism, but are major indicators of the change from a diagenetic to a tectonically controlled regime.