Investigation of the magnetic and dielectric properties and their anisotropy of salt rocks

Basic data for this project

Description

Salt rocks are an essential resource and play an important role in tectonic processes due to their special mechanical properties. Moreover, cavities in salt formations are used as storage and depository volumes for different materials. Knowledge of the formation, history, state and dynamics of salt rocks are therefore of great interest.Investigations of the rock fabric can give information on the internal structure and the deformation of salt deposits. A common method to characterize the rock fabric is measurement of the anisotropy of magnetic susceptibility (AMS). The AMS is generated by alignment of mineral grains. Advantages of the AMS method are the exact and fast measurement and the analysis of large rock samples. In the beginning, this method was only applied to rocks with a high content of ferromagnetic minerals. However, recent advances in the measurement equipment allow the investigation of weakly magnetic rocks today. In this project, the potential applications of the AMS method for characterizing salt rocks shall be examined. To this end, the minerals that dominate the magnetic properties are identified and the relationships between mineral fabric, chemical composition and magnetic properties are studied.A further aim of this project is to find out, if the petrological properties affect also the dielectric properties and lead to an anisotropy of permittivity. The dielectric properties determine the propagation of electromagnetic waves, which are commonly used to explore structures in salt deposits. The influence of mineralogical composition, fabric and deformation on the permittivity shall be examined. This can lead to conclusions, how deformed zones and petrological changes can be explored using electromagnetic waves.In order to reliably combine the results of the different analyses, the measurements of physical properties, chemical properties, and fabric should be done using the same samples.The results of this project can help to develop novel methods to investigate the deformational state of salt deposits, which is decisive for their utilization.