磁化率各向异性的原理及应用实例

摘要

磁化率各向异性(AMS)在地质领域中的应用极为广泛,可以用来研究古流向造成的磁性矿物的定向排列,以及构造应力作用引起的岩石内磁性矿物的定向重结晶、定向排列及韧性变形.本文介绍了AMS的基本原理和参数,并并介绍了前人及作者应用AMS详细分析研究了二个实例:(1)以假多畴(MD)高钛磁铁矿为主要载磁矿物的玄武岩样品的AMS变化及其对构造运动的响应;(2)以MD磁铁矿为主要载磁矿物的湖泊沉积物样品在沉积过程中AMS变化.AMS可以灵敏地检测样品中磁性矿物的定向排列,因此在在地质领域中具有很好的应用前景.%Anisotropy of magnetic susceptibility (AMS) has been widely utilized to study orientation of magnetic minerals due to the paleo-flow,and direction of magnetic minerals or their recrystallization caused by tectonic stress.We presented the AMS principle and parameters,and studied AMS changes in:(1) two basalt samples (unheated and heated) that have experienced tectonic deformation,with multidomain (MD) titanomagnetite as dominant magnetic minerals,and this is from a previous study;(2) lake sediments that are majorly characterized by MD magnetite.The results show that AMS can sensitively investigate orientation of magnetic minerals.