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Geochemistry of Thermal Waters of Continental Margin of Far East of Russia
Author(s) -
BRAGIN Ivan V.,
CHELNOKOV Georgy A.,
CHUDAEV Oleg V.,
KHARITONOVA Natalia A.,
VYSOTSKIY Sergey V.
Publication year - 2016
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12657
Subject(s) - geology , volcano , geochemistry , mantle (geology) , tectonics , continental margin , quartz , rare earth element , mineralogy , isotope , aquifer , groundwater , rare earth , paleontology , geotechnical engineering , physics , quantum mechanics
Studied waters belong to warm (T=30–50°C), alkaline (pH=8.9–9.3), low mineralized (TDS<235 mg/l) Na–HCO 3 or Na–SO 4 –HCO 3 thermal waters with high content of SiO 2 (up to 81 mg/l) and F (up to 3.9 mg/l), occur on modern volcano–tectonic rejuvenated areas of Eastern Sikhote–Alin orogenic belt. Low 3 He concentration as well as N 2 /O 2 and N 2 /Ar ratios exclude influence of deep mantle fluid. New rare earth element data constrain our understanding of water–rock interaction occurring in the water source region. Meteoric origin of waters is proved by stable isotope values varying from −71‰ to −136.1‰ and from −10.8‰ to −18.8‰ for δ 2 H and δ 18 O respectively. REE patterns reflect high pH, resultfing from water–rock interaction and oxidative conditions. Calculations of deep aquifer temperature using Na–K and quartz geothermometers show 116.8–131.1° C and 82.2–125.8°C respectively. Presence of deep faults both with abnormal thermal gradient (∼45–50 K/km) define unique geochemical shape of thermal waters of Sikhote–Alin, area, where no present volcanic activity is registered.