Structure of Flysch Cover as a Result of Detailed and Semi-Detailed MT Survey

lish Carpathians where the efficiency of reflection seismic survey is poor as a result of complex structure of the flysch cover of the Carpathian overthrust. The main aims of the surveys were recognition of Carpathians structure, but results of them were applied to studying structure and lithological differenciation of flysch cover. The meseurements were applied in two variants. First, MT sites were located separately along profile line with a step 1–3 km. In each sounding site short, 400 m continuous profiling was carried out to eliminate effects of small near-surface resistivity inhomogenities. Second, long (up to 15 km) magnetotelluric continuous profiling was carried out as an EMAP method. The quantitative interpretation was based on 1D Occam inversion and 2D NLCG algorithm. The 1D interpretation based on the least-square inversion was made too. An initial model for LSQ inversion was created based on available geological data and results of other geophysical methods. There were two ways of recognizing resistivity of flysch cover during interpretation. The first one is using the EMAP algorithm, the second one - using 2D inversion. A combination of those two methods gives good geoelectrical model.