Geophysical-geological investigations of rocks and soils
Case study: Investigation of a future quarrying area

The extension of an existing greywacke quarry is planned. Geophysical methods should help to estimate the thickness of the overburden and to detect weathering zones and tectonic fault zones.

The investigation was performed with 2D geoelectric resistivity measurements (mapping and sounding) in combination with calibration wells.

Fig. 1: Working face of the quarry

Along the lines, zones with weathered rocks could clearly be delimited from non-weathered materials. By arranging the single lines in an orthogonal grid, it was possible to interpolate the results of the different profile sections into a 3D cube. The estimated geological faults found in the data correlate very well with the striking and dipping directions of the faults seen in the quarry.

Fig. 2: Vertical resistivity section and geological model

Fig. 3: Horizontal resistivity section