The anisotropy of magnetic susceptibility as a method to study Quaternary deposits: theory and applications

Abstract

The anisotropy of magnetic susceptibility is used as a geophysical method, based on the non-uniform magnetic properties of rocks, within which it exploits the individual types of minerals, their quantity, and distribution in the rocks. The anisotropy of minerals may be a result of their crystalline structure or the shape of mineral grains. If the anisotropy is connected to the shape of the minerals, as in the case of magnetite, the axis of maximum magnetic susceptibility is perpendicular to the grain long axis. This indirectly allows determination of grain orientation in the rocks studied. Therefore, this method can be used to reconstruct the directions of transport of rock components, such as in loess, fluvial or ice-dammed sediments, and to determine the directions of ice-sheet movement based on glacial till studies. The method is also used in tectonic stress reconstruction, complementing the results of palaeomagnetic dating or the logging of borehole cores. The rapid, inexpensive measurement of anisotropy of magnetic susceptibility along with low human error in measurement has made this method competitive with traditional research methods