Piezo-remanent magnetism in rock and its field evidence

Abstract

Powdered natural magnetite was compressed under one-directional high pressure, and after the removal of the pressure, it was examined magnetically by means of an astatic magnetometer. A remanent magnetic vector was found in a direction perpendicular to the axis of the applied pressure. The present author proposed to call such a remanent magnetism caused by one-directional pressure Piezo-Remanent Magnetism (PRM) in order to distinguish it from TRM, DRM, CRM and other remanent magnetism. The effects of one-directional pressure on the remanent magnetism of rock have been examined with an artificial rock made of white cement in which fine ferromagnetic minerals were dispersed. It was found that both the intensity and the direction of remanent magnetization changed as the pressure increased. The field evidence showing PRM was found from several canyons where some rock specimens were sampled from the side wall. © 1962, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.