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Date submitted2022-04-13
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Date accepted2023-02-15
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Date published2023-08-28
The impact of secondary mineral formation on Na-K-geothermometer readings: a case study for the Valley of Geysers hydrothermal system (Kronotsky State Nature Biosphere Reserve, Kamchatka)
The temperature in the Valley of Geysers (Kamchatka) geothermal reservoir calculated using the feldspar Na-K-geothermometer has been steadily increasing over the past 10 years on average from 165 to 235 °C, which is close to the temperature values of a hydrothermal explosion of the steam and water mixture. For the analysis of chemical geothermometers, TOUGHREACT-simulation was used, with the help of which the previously known Na-K feldspar geothermometer was reproduced on a single-element model and new formulas were obtained for three Na-K geothermometers: zeolite, smectite, and based on volcanic glass. Data of chemical analysis for the period 1968-2018, in which the chloride ion is considered as an inert tracer of geofiltration processes, indicates that after 2007 a significant inflow of infiltration water (its mass fraction is estimated from 5 to 15 %) into the Geyser reservoir. It is assumed that the Na-K increased values of the feldspar geothermometer are not the result of the temperature increase in the Geyser reservoir, but the effect of smectite water dilution.
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Date submitted2010-07-28
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Date accepted2010-09-30
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Date published2011-03-21
Ingineering geological problems of high-rise construction with underground space development in Saint-Petersburg
- Authors:
- R. E. Dashko
- A. M. Zhukova
The history of high-rise construction is considered summarily. The main features of high-rise buildings and difficulties connected with theirs engineering and construction especially with underground space development and deep excavations in soft water saturated soils are characterized. Territorial construction guides «Residential and social high-rise buildings» prevail in Saint-Petersburg are analyzed in the context of recommendations for reliable basement choice. Brief description of Pre-Quanernary clays (Upper Vendian clays and Lower Cambrian clays) as basement for high-rise constructions are given. It is placed emphasis that the main feature of Pre-Quaternary clays is zone sequence of physical and mechanical properties and fissuring in depth. Physical and mechanical properties of Upper Vendian clays, Lower Cambrian clays and glacial clays are given. In addition, it is confirmed that glacial soils is not recommended to use as a basement for high-rise buildings.
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Date submitted2009-08-17
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Date accepted2009-10-18
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Date published2010-02-01
Geotechnical engineering and hydrogeological specifics of estimate high-rise buildings construction and operation conditions (in terms of local zone on the right bank of Neva river)
- Authors:
- A. M. Zhukova
In the paper specificity of geotechnical engineering conditions in the local zone of the right river Neva bank are considered. The influence of underground topographies of Pre-Quaternary soils roof formed by paleovalleys on the specificity of engineering geological profile is analyzed. Influence of tectonic faults on physical and mechanical properties of Upper Kotlin clays (Upper Vendian) which it is planned to use as the basis for high-rise constructions is considered. Negative influence of Low Kotlin (Upper Vendian) pressure water-bearing horizon on clay properties in the construction foundation and structural materials is investigated.