Interpretation of the Tribeč Mts. deep geological structure based on results of geophysical, mainly magnetotelluric modelling

Abstract

Magnetotelluric measurements (MT) in the southeast (SE) part of MT–15
profile in the frame of CELEBRATION 2000 project identified a subhorizontal zone with
higher conductivity in the depth of cca 2–6 km below the Tribeč Mts. surface. This zone is
interpreted as a complex of metamorphic rocks under the tectonically overlaying granites.
The original presuppositions collected through other geophysical methods on the existence
of such a complex are thereby confirmed. Apart from this finding, the MT measurements
identified other conductive zones in the Tribeč mountain range and its surroundings.
Those are close to the surface and belong to sedimentary rocks and volcanites. The
steep, narrow and deeply penetrating conductive zone at the north-western edge of Tribeč
Mts. can be interpreted as a deep Neogene shear zone. Subhorizontal conductive zone
in SE part of the cross-section under the volcanic complexes is interpreted as the older
mylonitized zone. This zone may be saturated by fluids, and is possibly of carbon origin
and mineralized, connected with volcanic activity.