Deep geoelectrical studies in the Finnmark and the Pechenga area by means of the ‘Khibiny’ source

Abstract

As part of the Soviet-Norwegian programme in geology and geophysics, an investigation of electroconductivity in the upper part of the Earth's crust was carried out in 1989–1991. The measurements were performed using an electrical dipole source, ‘Khibiny’, which is situated on the Kola Peninsula, close to the Norwegian border. A 26 kW car generator supplied square pulses with a peak to peak current of 100 A in the ‘Khibiny’ cable; at a frequency of 0.125 Hz. The distance between the source and the measuring points varied from 60 to 130 km. A stacking technique was applied to identify the weak electromagnetic signals. All the measurements were conducted using a six-component digital automatic station, ZAIS, produced at the Institute of Fundamental Physics of the USSR Academy of Science. As a result of the studies, several conductive current channels in the Pechenga structure on the Russian side of the border were traced into the Pasvik area in Norway. Detailed information on the deeper parts of the electroconductive structures in this area was obtained.