TY  - GEN
N2  - The helium isotope system is an established tool in hydrology for identifying mantle fluids in deep aquifers. This study applies the helium tracer system for the first time in shallow, unconfined aquifers of the Upper Rhine Graben. The Graben is a part of the Cenozoic Rift system of Western and Central Europe, a continental rift zone with unusually high geothermal gradients, making it an ideal region of Germany for geothermal energy development. The aim of this study is to develop a suite of natural groundwater tracers able to achieve a cost and effort reduction in geothermal prospection. The 3He/4He-ratio is therefore applied, as part of a multi-tracer approach including 3H, ?18O, ?2H, ?13C, 14C and 222Rn, to identify and locate fault zones with suitable permeabilities for power plant operation. Three target areas along the graben were studied, each located on one of the main fault lines.
A mantle-derived helium signature could be identified and separated from tritiogenic helium in a shallow aquifer in the north-west of the Graben. The mixing component of mantle-derived fluid in the shallow groundwater is calculated to reach up to 5%, based on the analysis of the 3He/4He isotope system. The employed method proves that the local permeability of the fault zone is high. The origin of the locally occurring upwelling of salinated water can be redetermined by the data.
A1  - Freundt, Florian
CY  - Heidelberg
AV  - public
TI  - Application of Helium Isotopes in Shallow Groundwaters for Geothermal Energy Exploration in the Upper Rhine Graben
Y1  - 2017///
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/23245/
ID  - heidok23245
ER  -