EXOTIC METAMORPHIC SCHIST FRAGMENTS IN THE OLIGOCENE DEPOSITS OF THE SILESIAN NAPPE (UKRAINIAN CARPATHIANS)

Abstract

The study aims at analyzing the petrographic composition of exotic metamorphic schist clasts in the Oligocene deposits filling the Silesian Nappe in the south-western part of the Ukrainian Carpathians and reconstructing their possible source area. The methodology includes petrographic, sedimentological and comparative geological methods. To achieve this goal, field research was carried out along the first right tributary of the Hysnyi Stream (the village of Uzhok, Velykobereznyanskyi district, Transcarpathian region) and petrographic analysis of the selected samples of the exotic metamorphic schist clasts included in the Oligocene debris-flow deposits was performed. The results of microscopic studies showed that these exotic rocks are represented by mica-quartz schist and garnet-muscovitebiotite-plagioclase-quartz schist with a low content of chlorite, carbonate and epidote. Mineral composition and structure/texture features suggest the rocks were metamorphosed under green schist and epidote-amphibolite facies. Similar exotic rock fragments were identified by Polish scientists in the south-eastern part of the Polish Carpathians in the Silesian Nappe, where possible source area of the exotic rocks is related to the Bukowiec Paleo-Ridge, which had been located between the Dukla and Silesian basins of the Carpathian sedimentary realm. Scientific novelty. For the first time, the petrographic composition and textural and structural features of the exotic schists fragments included in the Oligocene deposits of the Silesian Nappe in the Ukrainian Carpathians (area of the village of Uzhok, Ukrainian Carpathians) are described. These schists are similar to the exotic rocks included in the Oligocene deposits of the Silesian Nappe in the Polish Carpathians, which may indicate the same source area.