Experimental simple shear deformation of magnetic remanence

Abstract

A series of shear box experiments were run on magnetic rock analogues to determine how the remanence vector behaves during simple shear strain. Samples of silicone putty and silicone putty-magnetite and kaolinite-magnetite mixtures were given an anhysteretic remanence at high, moderate and low angles to the shear plane in order to determine if the magnetization deformed as a passive line marker or as if carried by actively rotating rigid grains. Out of a total of twenty experiments, twelve unequivocally contradict passive line behavior with an additional two experiments in strong disagreement with passive rotation of the magnetic particles. When compared to numerical modeling results, nine experiments clearly support active rotation of rigid magnetic particles. Thus, in settings where simple shear may have been a dominant component of deformation history, active rotation of remanence-carrying grains rather than passive line behavior may be an appropriate description of the deformation of the remanence vector.