The Isotopic Composition Of Hydrothermal Waters And Carbonate Deposits In The Adits Of The Baksan Neutrino Observatory
Kadebskaya, Olga Ivanovna (1); Dublyansky, Yuri Victorovich (2); Kadebskaya, Lyubov Yurevna (3)
1: Mining Institute of the Ural Branch of the Russian Academy of Sciences, Russian Federation; 2: Institutul für Geologie Innsbruck, Austria; 3: Faculty of geology, Moscow State University, Russian Federation
The adit of the Baksan Neutrino Observatory explores the situation in the Baksan Gorge (Central Caucasus) of the Kabardino-Balkarian Republic (Russia). The tunnel of this adit has been drilling since the beginning of the 1970s in the muscovite-chlorite-quartz shales of Kurmotau mount. There were opened several exits of thermal water in a fractured vein at the a distance of 3,700, 4,000 and 4,200 meters from the entrance. The isotopic composition of thermal water (δ18O, δ2Н) was δ18O-8.0, δD-86.1.
Analyzes of the isotopic composition of water were carried out at the University of Innsbruck (Austria) using Picarro’s L-2130-i laser and carbonates using a Delta PLUS XL mass spectrometer. Various mineralization has formed from these thermal springs for more than 30 years. That is similar in morphology to the cave formations, which were formed from hot solutions (20-50 ° C) and are mainly composed of calcite, as well as the constructed corallites of chlorine-sodium amphibole, magnesite, dolomite, magnesia calcite, tenardite, vanthgophyte, collectionjite, halite and sylvin.
The isotopic composition of C and O of carbonate sediments varies δ18O from -8.5 to -10.2 V-PDB and δ13C from + 1.4 to + 6.2 V-PDB (the analytical error for both isotopes is 0, 1 ‰ at the 1σ level).
A qualitative set of minerals, isotopy of C and O carbonates, as well as mineralization (8.2 g/l) and hydrocarbonate-sodium-chloride composition, hydrotherms allow to suggest that carbon dioxide in the mine space has a deep (magmatic, metamorphic) nature, and salt composition of solutions was formed from the buried evaporite complexes.