Relationship between Permanent Remanent Demagnetization and Stress in Crystallization Rocks

摘要

The effect of a generalized state of stress on the thermormanent magnetization (TRM) of rocks is being studied. Laboratory investigations have shown that application of stress experienced by the material. This property seemed ideally suited for use as the densing element in a passive piezometer. In a study of th e factors that control the magnitude of permanent stress-dominated magnetic changes, we are examining: (1) the effect of initial remanent intensity on the devrade in magnetization per increment of applied load; (2) the influence of chemical composition and gain diameter of the magnetic grains on the total piezomagnetic effect; (3) the difference between hydrostatic and non-hydrostatic loading on the reduction of remanent magnetization and (4) the effect of the orientation of the magnetic vector with respect to the greatest principal stress direction on the total piezomagnetic phenomena. Experiments were conducted on a gabbro and a diabase in which the remanent magnetization was controlled by pseudo-single-domain titanomagnetite grains.