Hydrogeological genesis and geothermal potential of the thermal springs of Hintertux, Austria

摘要

Europe's highest thermal springs are located at 1500 & x202f;m asl in Hintertux, Tyrol. Only 30% of the springs with temperatures up to 22.5 & x202f;degrees C are utilized. Future exploration and exploitation will require quantifying their resource potential and development of a conceptual hydrogeological model. A detailed and comprehensible explanation of the thermal anomaly has not yet been formulated. Methods including a combination of natural tracers, geochemical indicators and stable isotopes (delta O-18, delta D, delta S-34) have been used for identifying their genesis and their associated aquifers. Hydrogeological and hydrochemical investigations have been conducted from 2011-2018, evaluating groundwater from 14 surrounding springs and two tunnels. This study shows that the thermal water originates mainly from rock glaciers and meteoric waters from the Grierkar, entering swallow holes of the Hochstegen formation at the Grieralm. The thermal anomaly is caused by a groundwater component (20-40%) from footwall gneisses, probably connected to the marble aquifer by the Tux shear zones.