Interpretation of geochemical data from fumaroles and wells in the Námafjall geothermal field, Iceland and from fumaroles in the Mutnovsky geothermal field, Kamchatka, Russia

Abstract

The Námafjall area is a high-temperature geothermal area in North Iceland. In this report data from 1989, 1995 and 1999 for two production wells are used to calculate mineral equilibria and for comparison with actual temperatures, measured in the wells. Some data from fumaroles in this field are used to compare calculated gas geothermometer temperatures with measured temperatures. Gas geothermometer temperatures were also calculated for fumaroles in the Mutnovsky geothermal field (southern part of Kamchatka peninsula, Far East Russia) for comparison with available temperature data from the well`s logging. For samples from the wells there, geothermometers obtained subsurface temperatures of about 240-260°C. The gas geothermometers gave temperatures of 270-310°C (for wells) and 270-320°C (for fumaroles) in the Námafjall area. In the Mutnovsky geothermal area the H2S and CO2/N2 geothermometers gave temperatures of 280-310°C, which are close to reservoir temperatures.