Airborne Geophysical Investigation of the Environment of Abandoned Salt Mines along the Staßfurt-Egeln Anticline, German

The German Federal Ministry of Education and Research funded the research project ‘Dynamic processes in flooded or abandoned salt mines and their overburden’ in order to investigate possible consequences of salt-mine flooding. As an example, the 1200 years old town of Stasfurt, Germany, where the world‘s first potash mine was opened in 1852, was selected for this multidisciplinary research project. A number of destructive effects of the subsiding surface were caused by collapses of abandoned salt mine pits, the dissolution of salt in the mines and the pump-driven drainage system. These man-made effects increased the effect of natural salt solution along the south-western side of the Stasfurt-Egeln anticline. In summer 2007, BGR conducted an airborne geophysical survey covering the salt anticline. Helicopter-borne frequency-domain electromagnetic, magnetic and radiometric data were simultaneously collected. The aim of this survey was to acquire extensive data sets showing the regional (hydro-)geological structures down to about 100 m depth. The electromagnetic data, inverted to layered-earth resistivity models, revealed several hydrogeological features such as the distribution of salt water, areas of salt-water rise, buried paleo channels and freshwater influents. The airborne data also served as base-line data for ground follow-up studies and 3D (hydro-) geological modelling.