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.