望云山复式花岗岩体磁性组构特征及其动力学意义  

Magnetic fabric of Wangyunshan complex granite and its dynamic significance

作　　者：贾宝华[1] 刘耀荣[1] 

机构地区：[1]中国地质大学

出　　处：《岩石矿物学杂志》2002年第3期209-217,共9页Acta Petrologica et Mineralogica

摘　　要：为了分析望云山复式花岗岩体侵位时的动力学状态 ,对该岩体进行了岩石磁组构参数测定。磁化率的变化特征反映了望云山复式岩体侵位过程中构造环境的变化和单元岩石的暗色矿物组成及基性程度的高低 ;磁面理的产状与岩体形态和岩石单元分布相吻合 ,清晰地反映了不同构造单元岩浆侵位方式 ;磁线理指示岩体的侵位中心 ,线理表现形式不一 ,标示侵位方式与受构造应力的不同 ;晚期岩浆对早期岩浆中的磁线理有一定的改造作用 ,磁线理方向基本上反映了岩浆原始流动状态 ;从磁化率椭球参数可以看出岩浆侵位的应变状态 ;岩浆应力场分布体现了岩浆侵位方式及其所处构造环境。岩体岩石磁组构参数佐证了区域构造、围岩构造及岩体内部其他构造所反映的岩体侵位机制。The authors have determined magnetic fabric parameters of the complex granite in Wangyunshan with the purpose of analysing dynamic state of the granite in the process of emplacement. Changes of tectonic environments, composition of the dark minerals in the rock units and basification of the granite in the process of emplacement find expression in changes of magnetic capacities. The attitude of magnetic foliation, which clearly suggests the emplacement of the magma in different tectonic units, is consistent with rock shapes and distribution of rock units. Magnetic lineations indicate emplacement centers of the granite, and different lineations imply different ways of emplacement and tectonic stress. Magnetic lineations of the magma in the early period were altered by those in the late period, and direction of magnetic lineation shows primitive flowing state of the magma. The strain state of the emplaced magma is shown by ellipsoid parameters, and distribution of stress field of the magma reflects the ways of emplacement and tectonic environment. Mechanism of granite emplacement reflected by regional structure, wallrock structure and other structures is substantiated by magnetic fabric parameters of the granite.

关 键 词：花岗岩 磁性组构 动力学 侵位机制 望云山 构造应力 围岩 

分 类 号：P588.121[天文地球—岩石学] P318.4[天文地球—地质学]