Quantitative relationships between climate and magnetic susceptibility of soils on the Backa Loess Plateau (Vojvodina, Serbia)

Abstract

Magnetic properties of soils formed in and on loess substrate and their relation to climate are of general interest in paleoclimate and pedological research. The loess-paleosol sequences (LPS) in the Vojvodina region (Serbia) have been the subject of intensive study. On the Backa loess plateau (BLP), covering approximately 2500 km(2), six different soil types are observed. While the stratigraphy of the LPS has been investigated the relation between climatic factors and magnetic properties of surface soil have not yet been examined. In this study we analyze 50 samples of chernozem soils, which have been dominated by climatic factors during their formation. Previous studies have confirmed that the formation of magnetic properties in soils is related to climate, and especially rainfall, because of the response of hematite and goethite to different, climatically-driven regimes. The sensitivity of certain iron-bearing minerals to climate has also been documented in the literature. Climatic variables for the BLP were derived from six-decade national meteorological datasets. Low frequency magnetic susceptibility (chi) and frequency dependent magnetic susceptibility (chi(fd)) were determined for each site and compared to the mean annual precipitation (MAP), mean annual temperature (MAT) and the De Martonne aridity index (I-DM). The meteorological variables were interpolated to sampling points by Kriging method in ArcMap 10.1. Our results suggest that values of chi and chi(fd) both decrease from south to north and so does the precipitation. Thus, our work provides new evidence for the relationship between precipitation, temperature, aridity and magnetic properties of modern top soils. The obtained and analyzed data may help in the future to improve transfer functions of the relationship between magnetic susceptibility and climatic data.