Carbonate weathering


Timing of long term carbonate mobilisation in a limestone aquifer 

The project is part of the International Max Planck Research School for Global Biogeochemical Cycles (IMPRS-gBGC) in cooperation with the Friedrich Schiller University Jena.


IMPRS-gBGC


The Thuringian Syncline in the central part of Germany exposes deposits of the German Triassic Muschelkalk sequence consisting of limestone and dolostone beds. Partial dissolution, oxidation and iron redistribution is obvious in limestones along the slopes of the Saale valley (e.g., quarry Bad Kösen). These features are most prominent close to a Mid Quaternary valley floor (Elster terrace), decrease down-section following fractures, and reach a minimum close to the present groundwater table in a topographic level close to the present valley floor. This example of carbonate weathering transformation includes microbial influence on reprecipitation and intermediate storage of carbonate lining fault planes. Furthermore, this location has the important advantage that the timing of the 100 m depression of the ground water table, spread over >700 Ka, has a good age control due to both topographic dating of terrace formation and optically stimulated luminescence dating (OSL dating) of former river sediments that cover these terraces. The purpose of this case study is to define and quantify the important processes of carbonate weathering on a geological time scale and to assess the rates of material transfer involving CO2 over time.


phd student: Jens Kirstein