engleski

Spatial variability of soil magnetic susceptibility across Croatia

Magnetic susceptibility (MS) of soils and paleosols indicates the formation of secondary ferrimagnetic minerals (SFM) and pedogenic processeses. Comprehensive analysis of surface (0-10 cm depth) and sub-surface soils (20-30 cm depths) from over 750 locations in Croatia have been performed through measurements of low field mass specific MS (Xlf) and mass specific and percentage of frequency-dependent MS (Xfd) to determine spatial distribution of MS that can be used for provenance studies of soil, erosional processes as well as evaluation of soil pollution by heavy metals. It is also needed for the landmine-affected regions because it of the effects of soil magnetic susceptibility on metal detectors. Maps of soil MS in Croatia show two clearly differentiated distributions – Pannonian region versus karst area of Croatia. Differences are linked to geological sub-division of Croatia and its associated main soil types: the Mesozoic carbonate rocks of the Dinaric-Coastal karstic region with dominant red soils and kalkocambisols versus Pannonian region with dominant cambic, eluvial illuvial and gleyic soils mostly developed on clastic Neogene and Quaternary sediments. Soils developed on carbonate rocks have higher values of MS and Xfd compared to soils of Pannonian region. Magnetic properties of soils in karstic area are dominated by the presence of nanoscale superparamagnetic (SP) SFM grains produced in situ. Soil-derived magnetite gives major contribution to the magnetic enhancement in red soils. Primary ferrimagnetic minerals derived from geological sources dominate magnetic properties in only a minority of localities (mountainous areas composed of magmatic and metamorphic rocks). This is the first attempt to produce a soil magnetic susceptibility map Croatia that covers all dominant soil types in Croatia.

Magnetic susceptibility, Croatian soils, ferromagnetic minerals, karst, pedogenesis

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