Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Russian Geology and Geophysics

2017 year, number 1

GENESIS AND EVOLUTION OF HIGH-pCO2 GROUNDWATERS OF THE MUKHEN spa (Russian Far East)

S.L. Shvartsev1,2, N.A. Kharitonova3,4, O.E. Lepokurova1,2, G.A. Chelnokov4
1Tomsk Branch of the A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Akademicheskii pr. 4, Tomsk, 634055, Russia
2National Research Tomsk Polytechnic University, pr. Lenina 30, Tomsk, 634050, Russia
3Lomonosov Moscow State University, Geological Department, Leninskie Gory 1, Moscow, GSP-1, 119991, Russia
4Far East Geological Institute, Far Eastern Branch of the Russian Academy of Sciences, pr. 100 let Vladivostoka 159, Vladivostok, 690022, Russia
Keywords: High-pCO2 groundwaters, chemical and isotope compositions, water-rock-gas system, formation conditions, Mikhen spa, Khabarovsk Territory

Abstract

We present the chemical and isotope compositions of the water and gas phases of the unique Mukhen cold high- p CO2 spa. Estimated δ18O, δD, and δ13CTIC values and data on the geology and hydrogeology of the studied area indicate that the source of the groundwaters is meteoric waters, whereas carbon dioxide is of deep genesis and numerous regional faults are gas-feeding channels. Calculations of equilibrium reactions in the water-rock system show that the upper-aquifer waters (HCO3-Ca-Mg) with low TDS are undersaturated with carbonate minerals, montmorillonites, and aluminosilicates but are oversaturated with kaolinite, whereas the lower-aquifer waters (HCO3-Na) with high TDS are oversaturated with calcite, dolomite, and clay minerals but are undersaturated with main aluminosilicates. We propose a new concept of the formation of these groundwaters, demonstrating that the long interaction between rocks and groundwaters in the presence of CO2 and the considerable deposition of secondary minerals are responsible for the high TDS of the lower-aquifer waters (up to 14 g/L) and their geochemical type (HCO3-Na) and unusual isotope composition (δ18O = -25.2 ‰, δD = -69.0 ‰).