Electrical resistivity tomography as a modern tool for identifying loess covers – case study the Magdalenian site Wilczyce 10 (Sandomierz Upland, Poland)

Abstract

This research utilizes electrical resistivity tomography (ERT) in geophysical surveys conducted in the vicinity of a Magdalenian (Upper Palaeolithic) site in Wilczyce, Poland, focusing on loess covers and their litho- and pedological formation in relation to bedrock. The study yields several key findings: ERT effectively determines the depth of the rock mass. In 100-meter profiles, four geological layers are identified, with strong correlations with borehole data for the top three layers. Longer 200-meter profiles reveal three significant geological layers but at a reduced resolution. High-resolution ERT sequences enable precise boundary delineation between layers, uncovering distinct palaeorelief and identifying large palaeo-cavities. Achieving reliable results requires well-designed research plans and the use of the Schlumberger-Wenner or gradient array. The study also confirms the continuity of the L1 loess cover, variable thickness (ranging from 5 to 15 meters), and lithological identification through electrical resistivity imaging. The presence of a wavy palaeosurface beneath the loess layer indicates past landscape undulations, offering insights into geomorphological evolution and soil transformations in the presence of the loess mantle. While interglacial palaeosol (S1) was reliably detected, identifying lower-ranked mid-loess palaeosols posed challenges, highlighting complexities in soil formation processes and limitations in discerning underdeveloped horizons with electrical resistivity profiling. The study specifically examines the sequence of loess-palaeosol S0-L1-S1, providing valuable insights into the geological and palaeoenvironmental context of the Late Magdalenian site.