Investigation of the magnetic properties of soils in the Cisna-Wetlina Landscape Park

Abstract

A magnetic study of 16 samples of topsoil and 2 soil profiles (11 samples) in the area of Cisna-Wetlina Landscape Park was carried out. The whole collection of the samples represents typical Carpathian soils – brown and sour. Magnetic susceptibility, frequency, dependence of magnetic susceptibility, temperature dependence of magnetic susceptibility, thermal decay of saturation, isothermal remanent magnetization, parameters of hysteresis loop and anhysteretic remanent magnetization of the samples were measured in a laboratory. Mass magnetic susceptibility of topsoil specimens is below 40 $\cdot$ 10$^{-8}$ m$^{3} \cdot$ kg$^{-1}$, which indicates that the investigated area is probably not polluted currently. The study of the samples from two soil profiles reveals a slight enhancement of magnetic susceptibility in the upper horizons, presumably related to natural processes. The temperature dependence of magnetic susceptibility and saturation isothermal remanence of four soil samples show that the presence of iron sulphide minerals (pyrrhotite) and maghemite is associated with hematite. The occurrence of other iron sulphide minerals in the soil is also possible. The saturation isothermal remanence curves do not confirm the presence of magnetite. Studies of the hysteresis loop reveal a significant role of paramagnetics among magnetic minerals occurring in the samples. Hysteresis parameters (coercive force, coercivity of remanence, saturation magnetization, isothermal remanent magnetization) and anhysteretic remanent susceptibility allowed the authors to evaluate the grain size distribution and reveal the presence of pseudo-single domain (PSD) grains.