Balanced cross section of the Ukrainian Carpathians along Berehomet–Burkut

: pp. 72-87
Lviv Polytechnic National University
Subbotin Institute of geophysics of National Academy of Sciences of Ukraine

The presented balanced and restored geological sections demonstrate modern structure of the South–Western part of the Ukrainian Carpathians and quantitative parameters of the sedimentation basin development during the Lower Cretaceous and the Upper Cretaceous–Paleogene ages (~ 145–25 Ma). Balanced cross section is based on the field studies using modern geological maps and geophysical data. They result from the great amount of factual materials – published and collected from outcrops along the cross section. Data collection, processing and presentation were performed using modern computer programs and devices. Beddings and mesostructures (folds, joints, sliding plane) were measured at outcrops directly by mobile devices (smart phone) being equipped with geomagnetic and gravitational sensors, GPS devices and digital cameras, thus allowing it to be used as a geological compass, camera and navigator. This approach can increase the accuracy and productivity of work by several times. Processing of the collected data was carried out in an office, using program MOVETM by Midland Valley software company. This makes it possible to assemble a database in the attribute, vector and raster form with their  real coordinates, which facilitates the interactive construction of balanced cross–sections and the ability to edit or add data at any moment in the process of construction. The results can be presented in various formats, two–and three–dimensional for example, providing better information perception. The results of the undertaken study show the mechanisms of accretionary prism forming and parameters of sedimentary basins. The width of the sedimentary basin being determined on the basis of reconstructed cross section is at least 401 km, which is far greater than it was proposed in the previous studies. The contraction of the sedimentation basin due to a fold–thrusting process is 79.4% with the magnitude of deposits denudation established at 70.2%. The results obtained testify the specificity of regional tectonics style, namely, thin–skinned style which foresees fold–thrusting processes in the upper crust (sedimentary cover) of the Earth without significant involvement of accretionary prism basement rocks in this process. Also, the results of the study make it possible to compare various parameters of the models built by other authors not only on quality but also on quantitative basis.

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