GPR Measurements in Drifts at the Southern Part of the Allertal Salt Structure

The Allertal salt structure, used as repository for nuclear waste, was explored from the surface by seismic measurements, ground openings and boreholes. Due to the accuracy of these investigations, the internal salt structure is known. The complex geological structures (bent, folded, sometimes faulted layering of salt, potassium, clay, and anhydrite) in low-conductive salt can be mapped if distance and direction of reflecting objects are known. In focus of interest is the distribution of anhydrite layers in the center of the salt structure. Underground, GPR (Ground penetrating radar) is an efficient and precise nondestructive tool for the exploration of salt deposits. With geophysical results and some geological knowledge a three dimensional model of the salt structures can be created.