Magnetic characteristics of different soil types from Bulgaria

Magnetic studies of different soil types can provide valuable information a bout palaeoenvironmental conditions at the time they were formed. Results o f investigations of rock-magnetism of genetically different soil types, whi ch developed over varying time intervals (Meadow Chernozem - formed during the last 6000 years BP; Leached Cinnamonic soil -formed since the 3rd-2nd c entury BC and Pellic Vertisoil - the oldest, formed since the Late Pliocene ) are presented. The soil profiles of the Leached Cinnamonic and Pellic Ver tisoil are characterized by lower values of magnetic susceptibility, as com pared to that of the parent materials. It is shown that using percentage fr equency-dependent susceptibility (Xfd%) and viscous remanent magnetization (VRM), pedogenic alteration could be detected even in such circumstances. T he variations of the parameters measured along the depth of the studied Mea dow Chernozem soil profile are characterized by gradual smooth magnetic enh ancement, pointing to the absence of secondary redistribution of pedogenic magnetites. In contrast to this case the Two other profiles (Leached Cinnam onic and Pellic Vertisoil) show magnetically enhanced lower (illuvial) hori zons due to processes of acid destruction and re-precipitation of the origi nal pedogenic ferromagnetic minerals down the profiles. These specific magn etic properties are of particular importance in using susceptibility variat ions as a palaeoclimatic proxy record.