Paleoenvironmental reconstruction in geochemistry tries to reconstruct temporal changes in surface earth biosphere, geosphere, atmosphere and hydrosphere via changing chemical signatures in earth sediments. In the process of formation and dependent on their depositional environment all sediments interact with these one or more of these spheres leading to physical, chemical and biological processes influencing the abundance of elements and their isotopes within the sediment.
Earth’s mantle and crust as we see them today are the result of the dynamic behaviour and evolution of our planet. Interaction between mantle and crust occurring along plate boundaries as well as in intra-plate settings shaped the geochemical composition and diversity of both reservoirs. Research projects in this theme investigate material transfer happening on relatively short time-scales within subduction zones and the incorporation of crustal material on much longer time-scales in plume-related magmatism. Intracrustal processes, such as magma differentiation or the formation of layered igneous intrusions, are investigated in order to better understand material transfer within and into the crust.
This project aims at investigating the interaction between different reservoirs of our planet that led to the redox contrast between Earth’s interior and its surface. Particularly interesting are factors such as plate tectonics, mantle melting, volcanism and continent formation and how they contributed to or controlled atmospheric evolution. We study the long and short-term subduction recycling of surface redox signatures and the respective impact on the evolution of the mantle, as preserved in the stable isotope record of mantle-derived minerals through geological time. To address these issues, the project combines magmatic petrology, (micro-scale) mineralogy of highly siderophile and moderately volatile elements, geochronology and “non-traditional” stable isotope geochemistry. In particular high-precision Se isotope and coupled Se-Te concentration analysis is newly developed. Financial support for this project comes from a Starting Grant of the European Research Council to Dr. Stephan König.