Geology and Hydrothermal Alteration of the Hverahlid HT-System , SW-Iceland

The Hverahlid high-temperature system is located in the southern sector of the Hengill central volcano in SWIceland. Reykjavik Energy has today drilled three exploration wells into the geothermal reservoir in order to study its potential for electrical production. The 2000-2800 m deep wells that show a high-temperature system of 200°C -320°C below 600 m-1000 m depth. Lava successions dominate the strata with less hyaloclastite formations. Hydrothermal alteration ranges from totally fresh rocks in the overlying cold groundwater system through zeolite assemblage and into high-temperature mineral assemblage including chlorite, epidote, wollastonite and actinolite.