INFLUENCE OF GEOTECTONIC CONDITIONS ON THE COAL-BEARING FORMATIONS OF LVOV AND PRE-DOBROGEA DEPRESSIONS

• Datum: 2016
• 1. Verfasser: Ivanova, A.V.
• Format: Artikel
• Sprache: Russisch
• Veröffentlicht: Institute of Geological Sciences, NAS of Ukraine 2016
• Schlagworte: geotectonics; coal-bearing formation; peat accumulation; geothermics; metamorphism; salt coals
• Online Zugang: http://geojournal.igs-nas.org.ua/article/view/97284
• Назва журналу: Geological journal

 Geotectonic conditions of the development of Lvov and Pre-Dobrogea depressions located in the south-western part of the East European platform, at different orogeny stages are considered. The influence of geotectonic regime on conditions of peat accumulation and the formation of coal-bearing formations with certain genetic traits, manifested, in particular, in the transformation of organic matter and in the formation of real-petrographic composition of coals is analyzed. The main coalbearing region is confined to the Lower and Middle Carboniferous terrigenous strata. On the Late Visean-Late Serpukhovian stage within the Lvov and Pre-Dobrogea Paleozoic depressions in coastal marshlands of shallow sea the bog-marine coal-bearing subformation formed mainly of clarain composition of the reduced and transition genetic types. On the Late Serpukhovian-Late Bashkirian stage in the Lvov depression in swampy coastal lowlands located on the lagoon-delta shallow sea coast, the coals of the top coal-bearing subformation mostly of duroclarain composition, of transition and low-reduced genetic types were formed. The conditions of formation of Carboniferous coal-bearing formation in both regions allow us to consider it as paralic. Coals with signs of salinity are recorded in coal sediments of both regions. The coals of high sodium content are also found in paralic formations of the Middle Miocene of Nizhneprutsky bench adjacent to the south-west part of Pre-Dobrogea depression. Data analysis of vitrinite thermometry has shown that according to the level of geodynamic and geothermal activity during the formation of the Paleozoic sedimentary cover the Lvov Paleozoic depression characterized by normal geothermy. Pre-Dobrogea Paleozoic depression was classified as hyperthermal one.