磁铁矿岩的流变与磁化率各向异性
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摘要
在高温高压及慢应变率下使磁铁矿岩样品发生了流变。对此过程前后的磁性测试表明，产生了与流变过程相关的磁化率各向异性。进一步研究说明，这种“流变磁效应”，主要是由于岩样内磁性矿物颗粒在流变过程中，由大致等粒形且方向性不明显而转变为扁椭球形且具有了一定优选方位而造成的。地震孕育是在高温、高压及缓慢的时间过程中进行的，因此研究流变带来的物性变化对于地震前兆的认识至关重要。本实验结果从一个新的角度探索地震磁效应，具有理论和实际意义。
In the present study, some magnetite rock samples undergone a rheological process at some combined conditions of high-temperature,high-pressure andlow-strain-rate values. A series of magnetic measurements and analyses for thesesamples before and after rheological process indicates that a certain amount ofanisotropy of magnetic susceptibility induced in the process of rheology. Furtherinvestigations show that this kind of“effect of rock rheology on rock magnetism”ismainly caused by the change in grain shape of magnetite in rocks from isometricgranular to ellipsoidal and by the occurrence of their preferred orientation duringplastic deformation of rocks. Earthquake generates at high temperature ,high pressureand in long time-duration . For understanding earthquake precursors it is important toinvestigate the variation of physical properties cansed by the rheological process. Thepresent research is a new approach to the mechanism of seismomagnetism and so has theoretical and practical meaning .
In the present study, some magnetite rock samples undergone a rheological process at some combined conditions of high-temperature,high-pressure andlow-strain-rate values. A series of magnetic measurements and analyses for thesesamples before and after rheological process indicates that a certain amount ofanisotropy of magnetic susceptibility induced in the process of rheology. Furtherinvestigations show that this kind of“effect of rock rheology on rock magnetism”ismainly caused by the change in grain shape of magnetite in rocks from isometricgranular to ellipsoidal and by the occurrence of their preferred orientation duringplastic deformation of rocks. Earthquake generates at high temperature ,high pressureand in long time-duration . For understanding earthquake precursors it is important toinvestigate the variation of physical properties cansed by the rheological process. Thepresent research is a new approach to the mechanism of seismomagnetism and so has theoretical and practical meaning .
引文
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