Authors:
Chelnokov George
1
;
Bragin Ivan
1
;
Kharitonova Natalia
2
;
Chelnokova Berta
3
;
Aseeva Anna
1
and
Bushkareva Kseniya
1
Affiliations:
1
Far East Geological Institute FEB RAS, prospect 100-letya 159, 690022 andVladivostok
;
2
Far East Geological Institute FEB RAS, prospect 100-letya 159, 690022,Vladivostok, Lomonosov Moscow State University, GSP-11, Leninskie Gory, 119991 and Moscow
;
3
Institute of Medical Climatology and Rehabilitation Treatment (Vladivostok branch of FESCRPPR-RIMCRT), Russkaia st. 73-g, 690105 and Vladivostok
Keyword(s):
Mineral waters, REE, genesis, pCO2 waters, mineral precipitates, Sakhalin Island
Abstract:
Distribution and abundance of rare earth elements for Sinegorsky Spa of CO2-rich mineral waters and their mineral precipitates on the Sakhalin Island (the Far East of Russia) were studied. The main common features of waters from six boreholes are Na-Cl-HCO3 hydrochemical type, high total dissolved solids (16.2–23.1 g/L), a slightly alkaline pH (6.2–7.7), and Eh (-181 to 63 mV). The NASC-normalized patterns of all groundwaters are characterized by HREE enrichments and positive Eu anomalies, whereas some fluids are characterized by positive Ce anomaly and others have moderate negative Ce anomaly. The distinct positive Eu/Eu* in mineral waters indicates the nature of their water-rock interaction whereas Ce anomaly could be the result of the difference in groundwater circulation. Mineral precipitates are enriched with light REE and show a negative Eu/Eu* and positive Ce/Ce* anomalies which indicate redox controlled processes. The main processes controlling dissolved trace element behav
iour in water were established. It is argued that bicarbonate ion-pairs can also play an important role for the solution chemistry of HREE which explains the significant relative fractionation between REE observed in CO2-rich water. This work was supported by grants from Russian Science Foundation (RSF), project № 18-17-00245.
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