Influence of Hydrogeological Environment on Na-K-Ca, SiO2 and Mg-Na-K-Ca Geothermometers

Abstract

Influence of hydrogeologic environment on estimates of Na-K-Ca and SiO2 geothermometers is analyzed on the basis of hydrogeological and hydrogeochemical data of nearly 90 known, mostly low temperature geothermal systems. It is shown that for carbonate environment Na-K-Ca estimates are too low, while for clastic environment they have a tendency to be too high. SiO2 estimates for quartz with no steam loss open reasonable for a large variety of such systems. It is further shown that Na-K-Ca - SiO2 estimates cross plot can indicate whether carbonate or clastic rocks are present within a hydrogeothermal system. In some cases it reveals regional trends that may give additional suggestions considering the deep origin of a vien source. The role of Mg correction Na-K-Ca estimates is analyzed as a function of the hydrogeologic environment.