Rozpoznanie złoża piaskowców budowlanych z wykorzystaniem geofizycznych badań elektrooporowych i georadarowych

The paper presents the application of Vertical Electrical Sounding (VES) and Ground Penetrating Radar (GPR) into recognition of the geometry and vertical differentiation of a deposit of color sandstones that are commonly used as elevation stones in building industry. The investigations covered sandstones of Lower Cretaceous age (Albian) that occur at the foothills of the Che³mo Mt. near Kolonia Grabowie (Radomsko district, £ódŸ province). The former quarry of Grabowie is situated in the forest area of the landscape park and this blocked further exploitation from the documented deposit. On a limited scale sandstone is still quarried form the southern edge of the old quarry. However, poor recognition of the deposit hampers the effective exploitation. The objective of the geological investigations was to examine a new part of the deposit including identification of the roof and the bottom of sandstone complex, the thickness of overlying rocks, location of faults and weathered zones, as well as recognition of the lithology down to a depth of 8 m below ground surface. Resistivity distribution in the study area was assessed with the use of VES. Much higher resistivity of sandstones as compared to surrounding rocks was advantageous. Owing to high resolution GPR, the deposit boundaries could be delineated and the stratification within the sandstone complex could be represented. The investigations resulted in construction of 2D models of the deposit and surrounding rocks and gave information on the lithology.