Role of Magnetic Interaction in Sediments

Abstract

The effect of the magnetic interaction between the magnetic carriers was estimated by a simple pair model, where the remanences of post depositional origin was assumed. The theory predicts a large concentration dependence of the intensity of the remanence for a very low concentration range (packing fraction ≤ 0.1 %) if the magnetic particles are small and have a single domain structure. The effect decreases with the increase of the grain size. In order to check the validity of the theory, the intensity of the remanence acquired during the consolidation of artificial sediments was measured as a function of the concentration of fine grain magnetites in a magnetite-talc mixture. The result indicates the large concentration dependence of the remanence intensity. The validity of the various methods, which have been used to normalize the NRM in sediments to obtain the relative intensity change of the earth's magnetic field, was discussed on the basis of the present result. © 1983, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.