Paleoenvironmental investigations in geochemistry try to reconstruct temporal changes in Earth’s atmosphere, hydrosphere and geosphere system. Formation and deposition of any sediment thus interacts with one or more of these spheres leading to physical, chemical and biological processes influencing the abundance of elements and their isotopes within the sediment. 
Of particular interest in this theme are the profound changes during the Archean-Proterozoic transition, when oxygen levels rose dramatically during a first Great Oxidation Event (GOE: 2.45 to 2.32 Ga). To better resolve Earth’s oxygenation before the GOE we apply different isotope systems of redox-sensitive elements as for example Cr, Fe, Mo and W. Especially the combination of these different proxies might allow us to set better constraints on the early rise of free oxygen in the hydro- and atmosphere.
 

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 (isotope) 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 a much longer time-scale in plume-related magmatism. The application of non-traditional isotope signatures like Ti, Cr, Fe, Zn and Mo offer exciting new insights into processes taking place in the deep Earth as for example partial melting and melt-rock interaction. Combination of such data with radiogenic systems offers additional understanding of the timeline of the investigated processes.

The advancement and development of Multi-Collector ICPMS some 20 years ago offered the possibility to measure isotopic compositions of almost the complete periodic table of elements with the introduction of the so-called non-traditional stable isotope systems. The potential to use different elements and their isotope variations as proxies for geological processes is still under exploration. Recent findings of exciting new isotope variations even in high-T environments like Earth’s interior demand ongoing analytical development to increase accuracy and precision.