磁组构的分离与岩石构造变形分析  

Magnetic fabric separation and analysis of rock tectonic deformation

作　　者：曹新文 孙知明[1] 黄宝春[2] 李海兵[3] CAO XinWen;SUN ZhiMing;HUANG BaoChun;LI HaiBing(Key Laboratory of Paleomagnetism and Tectonic Reconstruction of Ministry of Natural and Resources,Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Orogenic Belt and Crustal Evolution,Ministry of Education,School of Earth and Space Sciences,Peking University,Beijing 100871,China;Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]自然资源部古地磁与古构造重建重点实验室,中国地质科学院地质力学研究所,北京100081 [2]北京大学地球与空间科学学院,教育部造山带与构造演化重点实验室,北京100871 [3]自然资源部深地动力学重点实验室,中国地质科学院地质研究所,北京100037

出　　处：《地球物理学报》2022年第2期448-470,共23页Chinese Journal of Geophysics

基　　金：国家自然科学基金(91855216,92055205);中国地质调查局项目(DD20190059)联合资助。

摘　　要：目前实验条件下获得的AMS(磁化率各向异性)是岩石内所有磁性矿物磁化率各向异性叠加的综合响应,详细的岩石磁学和构造地质学的综合分析表明常规AMS测试结果通常无法揭示岩石复杂的构造变形过程.本文综述了运用非磁滞剩磁各向异性(AARM)、低温AMS(LT-AMS)和高场AMS(HF-AMS)等实验方法对岩石AMS组分进行分离,可以定量获取不同磁性矿物的磁组构贡献,进而解释其不同的变形特征.在此基础上阐述了近年来针对不同磁性矿物组合的AMS分离方法的理论技术创新和进展及其在岩石构造变形特征分析中的应用前景,讨论了常见磁性矿物单晶的岩石磁学性质及各向异性度(P;)与形状因子(T)在揭示岩石变形特征中的复杂性与局限性,最后举例并分析了磁组构分离技术在造山带岩石构造变形分析中的应用.Both detailed rock magnetism and structural analysis suggest that the routine anisotropy of magnetic susceptibility(AMS)measurements can not suffice for the interpretations of complicated tectonic deformation,because AMS is the result of all the magnetic minerals contribution.In this paper,we reviewed the measurements of anisotropy of anhysteretic remanence(AARM),low-temperature AMS(LT-AMS),and high-field AMS(HF-AMS)to separate different components in the AMS.Thus,contribution of multiple magnetic minerals to AMS can be obtained quantitatively,which will contribute to different tectonic interpretations.On this basis,we described the theoretical basis,technological innovations,and its application prospect of AMS separation methods for the different magnetic components in deformed rocks.We also discussed the complexities and limitations of the shape factor(T)and the degree of anisotropy(P;)in grain-scale single crystals for the interpretation of tectonic deformation.Finally,some typical examples of separation of magnetic fabric and its applications in orogeny strain analysis were listed.

关 键 词：磁化率各向异性(AMS) 磁组构分离 构造变形 

分 类 号：P318[天文地球—固体地球物理学] P542[天文地球—地球物理学]