The investigation of specific isotope systems represents an important tool in clarifying the origin of lithium in the hot deep waters in Germany. Especially, isotopes of strontium, lithium, and boron play an important role.
The deep geothermal water in the Upper Rhine Graben is characterized by light lithium and boron isotope signatures, which are an order of magnitude below the corresponding marine signatures (δ7Li = 31 ± 0.5 ‰; δ11B = 39.5 ± 1.0 ‰ according to Vengosh et al., 1991; Millot et al., 2010).
The study of the above-mentioned isotopic systems occupies a central position in UnLimited. Most of these analyses are performed by the scientists of the University of Göttingen.