A combined application of two independent direct current geoelectric methods, potential gradient mapping (PM) and magnetometric resistivity (MMR), is proposed for the investigation of high‐resistivity basement structures. From a one‐dimensional relation between horizontal electric and magnetic fields (due to currents originating from point electrodes placed on the surface of a two‐layered half‐space having a high‐resistivity basement) several advantages of the combined PM‐MMR method are shown for two‐dimensional and three‐dimensional basement structures. Three‐dimensional models have been studied by analogue modeling experiments. This new mapping method embraces two parameters: the horizontal electric conductance map, derived from the ratio of the related electric and magnetic components, and the gradient map of their product. A close relation between structural forms and anomaly maps is obtained by using two orthogonal source‐electrode layouts. Based on model results a two‐channel measuring instrument was developed. The method and the instrument were tested near Sopron where a gradual deepening of, and faults in, the Paleozoic basement were found.
|Number of pages||21|
|Publication status||Published - May 1987|
ASJC Scopus subject areas
- Geochemistry and Petrology