The relationship of rheology of magnetite rock with anisotropy of magneticsusceptibility

In the present study, some magnetite rock samples undergone a rheological p rocess at some combined conditions of high-temperature, high-pressure and l ow-strain-rate values. A series of magnetic measurements and analyses for t hese samples before and after rheological process indicates that a certain amount of anisotropy of magnetic susceptibility was induced in the process of rheology. Further investigations show that this kind of "effect of rock rheology on rock magnetism" is mainly caused by the change in grain shape o f magnetite in rocks from isometric granular to ellipsoidal and by the occu rrence of their preferred orientation during plastic deformation of rocks. Earthquake generates at high temperature, high pressure and in long time-du ration. For understanding earthquake precursors it is important to investig ate the variation of physical properties caused by the theological process. The present research is a new approach to-the mechanism of seismomagnetism and so has theoretical and practical meaning.