Geothermal conditions south of the Kaiserstuhl [Geothermische Verh?ltnisse südlich des Kaiserstuhls]

摘要

The District Authority (Regierungspr?sidium) Freiburg interpreted reflective seismic data for the region of Hartheim south of the Kaiserstuhl (Upper Rhine Graben). The seismic data were used to determine the position of the inner fault zone of the Upper Rhine Graben in this area, combined with parameters of depth and thickness for the most important hydrogeothermal reservoirs of the Hauptrogenstein (Middle Jura), Oberer Muschelkalk and Buntsandstein. The inner fault zone shows an offset of up to 3 000 m, that separates the deep subsided inner zone of the Upper Rhine Graben (basin of Hartheim) in the west from the shallower parts in the east (Tuniberg, Freiburger Bucht). In the subsided inner zone of the Upper Rhine Graben temperatures of 130 °C at a depth of 3 000 m or 150 °C in a depth of 3 500 m can be expected. Estimated hydraulic conductivities for the aquifers of the Hauptrogenstein and Oberer Muschelkalk average at T/H=2·10-6 m2/s with significant standard deviations. The Buntsandstein delivered only a few values. The deep seated waters in the inner zone of the Upper Rhine Graben are dominated by natrium and chloride, showing total dissolved solids (TDS) of several 10s g/l. Waters with the highest value for TDS can be found in the Hauptrogenstein aquifer.