Stages of geodynamic development of the territory of the Lviv-Volyn coal basin

Abstract

The purpose of this work is to analyze geodynamic processes of origination, geological development, and Post-Carboniferous alteration of Carboniferous deposits of the Lviv-Volyn Basin. The methodology is based on historical-geological and facies studies. It includes a comparison of the capacities and distribution of deposits of different ages in the region as well as a dynamic analysis of the formation of coal deposits in the basin. The conducted investigations showed that the territory of the Lviv-Volyn Basin had a special history of geostructural Pre- Carboniferous development that sufficiently influenced its formation and caused geotectonic and morpho-structural alterations. The formation of this region resulted from complex and prolonged, during several tectonic stages, processes of interaction between the zones of tectonic activity and regional fractures connected with it. Activation of these zones happened to be at definite periods of geological time and was manifested in the development of concrete geostructural elements. Tectonic events of all periods of sedimentary cover formation were individual and unique. They became the basis for the formation and changes in the overall structure of the southwestern edge of the East European Platform and, in particular, the Lviv-Volyn Basin, as part of the Lviv-Lublin Trough. With other geostructural relations, the tectonic structure of the basin would be significantly different. In the Paleozoic era, the structural elements of the north-western and south-eastern extension played a decisive role in the formation of this territory. Originality. Based on the analysis of the thickness of the region's deposits of different ages it was shown that forces of horizontal compression affected the coal-bearing unit during the geological formation of the basin. During their influence, there was a depression of the territory, which led to the formation of primary tectonic forms and Post-Carboniferous main tectonic and morphological structures. The coal-bearing deposits have undergone repeated wash-outs, resulting in a shortening of the section and a significant decrease in the volume of the productive part of the coal formation.There is a graphic representation of the change dynamics in the location of crystalline basement surface at different stages of tectonic formation of sedimentary thickness of the basin, whose inclination was different. Practical significance. The conducted research determined stage-by-stage geodynamic development of the territory of the Lviv-Volyn Basin. Five distinct stages can be identified in the formation of coal-bearing deposits, from their origin to their eventual erosion. These stages reflect the unique features of coal formation and geodynamic processes. The geological map of the Pre-Mesozoic deposits of the carboniferous coal-bearing megaformation in the Lviv-Lublin Basin provides insight into the geological structure of the Lviv-Volyn and Lublin Basins, highlighting both similarities and differences. These findings contribute to our understanding of the formation processes of Carboniferous coal-bearing formation in the Lviv-Volyn Basin. They also expand our knowledge of coal distribution, coal seam morphology, and coal thickness structure, which can be used to compare with coal-bearing formations in other basins.