Study of Anthropogenic Denudation of Loess in Poland - Methodological Aspects

Poręba, G. J.¹, Śnieszko, Z.², Moska, P.¹

¹Department of Radioisotope, Institute of Physics, Silesian University of Technology, Gliwice, Poland

²Faculty of Earth Sciences, Silesian University, Sosowiec, Poland

Study of anthropogenic loess diluvium in Poland by the radioisotope methods has more than 25 years old history. As a first method to date humus of fossil sols bellow the diluvium was used radiocarbon method. This method needs a lot of corrections, e.g. based on archeological data. New quality is connected with using OSL method to date sediment samples. By this method could be dated diluvium sediment taken directly from the diluvium layers above dated by radiocarbon method fossil soils. Application of the Cs-137 method allows to recognize the youngest diluvium sediments. The simultaneously using of those three methods allow to reliability establishing of phases of soil erosion for the specific loess areas. The oldies diluvium were formed 5000 BP and this is connected with Neolithic agriculture (Funnel Beaker culture). Second phase of intensification of soil erosion processes was between IX and X century and is connected with Middle Ages developing of agriculture. Beside this, for the nearest area of pre-historical settlement are also visible intensifications of soil erosion connected with other phases of colonization (Lusitanian). Doubtless, the highest intensity of soil erosion processes and generality of this processes are connected with beginning of tillage of root plants and deep ploughing. Precisely establishing of intensity of soil erosion processes is possible only for last 50 years with aid of Cs-137 method. The results of study of soil erosion obtained by the Cs-137 method carried out on representative area of South-West Poland loess areas for last 50 years are between 0.2 and 8.1 mm lost of soil per year. The obtained values of soil erosion strongly depends on slope angle and localization on the slope. In geological profiles at the base of the slope diluvium sediments where exists different age diluvium sediment, the thickness of the sediments could achieve up to 4-5 meters. The thickness of diluvium sediments connected with last 50 years is about 1 meter. In the presentation and article will be presented selected examples to illustrate of intensification of soil erosion by the historical agricultural cultivation on the loess areas in Poland.

Corresponding author: Poręba, G. J. | FALI MAIL !!!