| Библ. ссылка: | Novikov D.A., Kopylova Y.G., Vakulenko L.G., Sukhorukova A.F., Pyrayev A.N., Maksimova A.A., Dultsev F.F., Chernykh A.V. ISOTOPE GEOCHEMICAL FEATURES OF OCCURRENCE OF LOW-RADON WATERS "INSKIE SPRINGS" (SOUTH-WESTERN SIBERIA) // Известия Томского политехнического университета. Инжиниринг георесурсов. - 2021. - Vol.332. - Iss. 3. - P.135-145. - ISSN 2500-1019. - EISSN 2413-1830. |
| Реферат: | eng: The relevance of the research lies in obtaining the first isotope-geochemical data on natural waters and host rocks of the "Inskie springs" occurrence of low-radon waters. The aim of the research is to study the peculiarities of chemical composition of natural waters and water-bearing rocks and obtain the first information on the total alpha- and beta-activity of natural waters, the activity of Rn-222 and the isotopic composition of delta D, delta(18)(O), delta O-13, U-234, U-238, Ra-226 and Ra-228. Methods. Sampling was carried out in accordance with generally accepted techniques. Laboratory study of the chemical composition by titrimetry, ion chromatography, inductively coupled plasma mass spectrometry was carried out at the Problem Research Laboratory of Hydrogeochemisby of the TPU School of Natural Resources. The analysis of the complex of isotopic ratios delta D, delta O-18, delta C-13(DC) of waters and dissolved inorganic carbon was carried out at the Center for Collective Use of the IGM SB RAS using the Isotope Ratio Mass Spectrometer FinniganTM MAT 253. Data on the total alpha- and beta-activity of natural waters, as well as the activities of U-234, U-238, R-226 a u Ra-228 were obtained using gamma and alpha spectrometry (after preliminary radiochemical sample preparation). Results. In 2019, 35 km from Novosibirsk, far from the known granite massifs, the "lnskie springs" occurrence of low-radon waters was discovered, referring to the waters of the regional fracture zone. The work presents the first results of their geochemical studies. The waters are moderately fresh HCO3 Mg-Ca with a total mineralization from 389 to 536 mg/dm(3) with a silicon content of 4,14-8,61 mg/dm(3). They are characterized by pH from neutral to slightly alkaline (7,1-8,4), oxidative geochemical environment with Eh +205,3 -+231,8 mV and O-2dissolved content of 6,24-12,26 mg/dm(3). The activity of Rn-222 varies in the range of 7-149 Bq/dm(3); contents: U-238 from 2,83.10(-3) to 4,13.10(-3) mg/dm(3) and Th-232 from 2,39.10(-6) to 1,16.10(-6) mg/dm(3). According to the isotopic composition, the origin of water is infiltration. The range of delta(18) O values in waters varies from -17,1 to -16,7 parts per thousand with delta D values from -128,4 to -126,2 % and delta C-13 variation is in the range of -13,1 to -10,3 parts per thousand The host rocks are dark gray (to black) shales, sometimes gray, with a small admixture of silty and sandy-silty material. The isotopic composition of calcite in the host rocks is characterized by similar values: delta C-13 varies from -3,1 to -2,7 parts per thousand, delta O-18- from 17,2 to 18,4 parts per thousand Weathered clay shales are characterized by lower contents of delta C-13 (up to -11,0 parts per thousand) and delta O-18 (up to 13,9 parts per thousand). Also, according to the results of geochemical studies, these samples are characterized by a significant decrease in the content of all trace elements (except for U), which indicates active interaction of waters with the host rocks.
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