Hydrothermal-bacterial structures with a brachiopod fauna on the surface of Tessel paleovolcano (South coast of Crimea)

Research subject. For the first time, results of a study hydrothermal-bacterial carbonate structures and shell bank brachiopods on surface effusive sequence Late Triassic Tessel paleovolcano are presented. Methods. Petrographic thin sections were studied using an Olympus BX 5 microscope with DP 12 camera. Geochemical investigations performed according to conventional methodology by inductively coupled plasma mass spectrometer (ICP-MS). The isotopic composition carbon was determined isotope ratio spectrometry (IRMS) Deltaplus Advantage instrument. paired EA Flash1112 analyzer TC/EA convector. When measuring, NBS-19, NBS-18, IAEA-C-3 standards used. Results. data obtained geology, geochemistry, materials confirm existence symbiosis between protozoa. primary formation organic matter bacterial occurred due processing paleofluids community bacteria archaea. These organisms created carbonate, sulfide in suboxide environment hydrogen methane. biocenosis characterized poor taxonomic high biological productivity. edifices took place during period volcanic activity continued breaks eruptions. geochemistry buildups deep nature paleofluids. Norian age paleovolcanism from finds terrigenous- Worobiella ex gr. caucasica Dagys ammonite Megaphyllites insectus (Mojsisovics). Conclusions. According geological features, material belongs ancient hydrocarbon seeps-carbonate. Based their genesis material, these formations should be referred as methanoliths. Signs allocation similar other time intervals regions given. Emissions fluids methane may have been related causes “global extinction”.