Dobšice a Zeměchy - perspektivní sprašové lokality pro paleoenvironmentální výzkum svrchního pleistocénu
Abstrakt
Sites Dobšice (Southern Moravia) and Zeměchy (Central Bohemia) represent some of the most important currently exposed loess profiles in Czech Republic, which cover almost the whole Upper Pleistocene. Magnetic properties (concentration and grain size of magnetic minerals) of researched sequences are influenced by intensity of pedogenetic processes.
The strongest magnetic signal was measured in interstadial steppe chernozems, whereas the interglacial forest parabraunerde shows weaker signal. Based on correlation of magnetic records with Rb/Sr and Sr/Ca ratios, strong relationship between pedogenesis and intensity of weathering (leaching) was found.
Nevertheless, in comparison with magnetic measurements, the highest values of ratios were found in interglacial soils, whereas interstadial soils show weaker weathering (leaching) intensity. Geochemical results also suggest weaker leaching intensity than in Zeměchy, probably due to drier condition in the Southern Moravia in comparison with Central Bohemia.
Combination of mineral-magnetic and geochemical analyses therefore provides more complex information about paleoenvironmental changes during the Upper Pleistocene