SHIFT INDICATORS IN THE TRANSCARPATHIAN DEEP FAULT ZONE

Abstract

The 1990s marked the beginning of extensive tectonophysical research on the Ukrainian Carpathians based on a combination of kinematical and structural-paragenetic analyses. The in-situ subvertical splits with a north-eastern orientation were found out to outnumber the north-westernly oriented ones, apparently due to the north-eastern compressional stresses which followed the Carpathian folding. The inclined splits are of a similar orientation. There are, however, numerous sublatitudinal and submeridional tectonic dislocations in the Transcarpathian trough. These can be referred to formerly subvertical splits which were reversed when folding was in progress. Other dislocations in the Carpathians were caused by the movements in the foundation underlying flysch. This type of dislocation can be illustrated by the Latorytsko-Stryiska strike-slip fault zone whose genesis is associated with a border zone between the two nappe systems in the Outer Carpathians. Due to the presence of different structures the compression of the basin was inhomogeneous in different sections, which resulted in the formation of two different nappe systems divided by the Latorytsko-Stryiska strike-slip fault zone. The tectonic splits and faults in the Ukrainian Carpathians are believed to have been caused mainly by uniform stress; however the evolution of each tectonic area proceeded in an individual way, depending on a number of factors. The interplay between the geodynamical evolution of the Transcarpathian deep fault and the formation of faults in the bordering Carpathian nappes is of particular scientific interest. A tectonic fault with a north-eastern orientation was found by the author in the Rakhiv nappe during the fieldtrip in 2013. The scheme by M. Gzovskiy having been applied, the relative position of the newly found fault and the Transcarpathian deep fault may suggest dextral strike-slip movements in the Transcarpathian deep fault resulting from transpression. This assumption fits in with the new dynamo-kinematical interpretation of Neogene volcanism in the Transcarpathians, according to which uniform submeridional compression in the Carpathian fold system accounts for the right-side shear zone in the Transcarpathians. It is the Transcarpathian deep fault that makes the north border of the shear zone. These data shed some light on the region's geodynamical evolution, which, however, requires further field research.