Geochemical study of the Geysir geothermal field in Haukadalur, S-Iceland

Abstract

The Geysir geothermal field in Haukadalur, S-Iceland is one of Iceland's most famous tourist attractions and a treasured historical place. The geochemistry of the field was studied by the compilation of all older data and by sampling and analysis of two hot springs and three wells nearby. The main aim of the study was to evaluate the reservoir temperatures and geochemical properties of the field and assess possible changes by time. Further the project aimed at studying the relationship between the Geysir geothermal field and exploited wells in the neighbourhood. The future protection of the field was also a point to be considered in course of the study. The geothermal waters are sodium chloride and bicarbonate waters with high contents of fluoride and boron indicating reactions with acidic volcanic rocks. The radioactivity of the water is also found to be 10-100 times higher than encountered in most other geothermal fields in Iceland. The calculated quartz geothermometer value for water from the Geysir hot spring indicates minimum reservoir temperatures of 240°C. Other hot springs give lower values probably due to starting precipitation of silica ...