Integrated environmental isotopic, hydrogeochemical and hydraulic investigations of the Malm aquifer in the Bavarian Molasse Basin

The Malm aquifer (Upper Jura) in the Bavarian Molasse Basin hosts a great potential of geothermal energy for hydrothermal heat usage and the production of green energy. However, up to now there is only little understanding of the local and regional flow regimes and the reservoir of the Malm aquifer.

Therefore, the objective of this study is to assemble geologic, hydrologic, isotopic, and geochemical information to develop an understanding of this complex hydrogeological deep groundwater system. Furthermore, we want to test our hypothesis if the Malm aquifer is composed of a mixture of several water types: a) a recent meteoric fresh water; b) a fresh glacial meltwater with an isotopic composition depleted in delta-18O and delta-2H; c) an “extreme” water component enriched in delta-18O and delta-2H; and d) a very old water component.

As a result, we want to shed light on past and present flow dynamics that will contribute to the effective management of the deep Malm groundwater system. To reach these goals geochemical, isotopic, and hydraulic information as well as additionally performed sampling campaigns and cutting-edge analytical tools are used extensively to delineate the groundwater flow and mixing of the carbonate-rock water aquifers of the Malm.