Rock magnetism and soil magnetic susceptibility

Abstract

Information support of modern agriculture and ecology forms a demand for ever higher requirements for efficiency and density of the sampling network. This fact determines the spread of high-performance methods of soil research, among which are magnetometric ones. However, these methods have a number of limitations associated with the existence in soils of ferromagnets of non-pedogenic nature. The purpose of the study is to show the patterns of spatial and profile distribution of soils with high values of magnetic characteristics, inherited from parent rocks as a result of pedogenesis. The research used: determination of specific magnetic susceptibility using kappabridge KLY-2, determination of volumetric magnetic susceptibility with kappameter KT-5 and induction of magnetic field by proton magnetometer MP 203. The study was conducted at two objects located in the central part of the Ukrainian shield region. Studies have shown that soils developed on the weathering crust are characterized by certain features of their magnetic properties. First of all, it depends on the petromagnetic parameters of the source rocks. On magnetic rocks, the MS of soils is determined primarily by inherited magnetic minerals. The magnetic susceptibility of such soils has two maxima. The first is in the upper part of the profile, where it is determined by the sum of pedogenic and terrigenous magnets. The second is located in the lower part of the profile, which consists almost entirely of weathering products.