APPLICATION OF SILICA GEOTHERMOMETER IN LOW-TEMPERATURE HYDROTHERMAL AREAS IN ICELAND

It has been established from temperatures measured in drillholes that the amount of dissolved silica in thermal waters at depth in the low temperature hydrothermal areas in Iceland is governed by the solubility of chalcedony when temperatures are below about 110 degree C. The study of low temperature hydrothermal areas in Iceland has much economic significance, since these waters with temperatures as low as 56 degree C are used extensively for house heating and greenhouse farming. Hydrogeochemistry plays an important role in surface exploration of thermal manifestations in these areas. This exploration forms the basis for judgment of the probability of economic subsurface recovery of thermal water by drilling. Refs.