Formation and differentiation of the continental crust
The formation and differentiation of the continental crust were essential steps for life to conquer landmasses and ultimately to the evolution of human habitats. We will study how these processes operated form early continental crust formation and how this is manifested in the rock record. We will investigate the different trace element signatures of fluid-fluxed melting and dehydration melting at mid- to lower-crustal conditions. Polyphase inclusions as well as glasses representing products of trapped melts (“nanogranites”) in peritectic minerals feed an exciting new research direction combining petrology with in-situ geochemistry to study the differentiation of the continental crust. We will also evaluate how and where carbonate melts are formed in the crust. Accessory phases play a crucial role during crustal melting and will determine whether incompatible elements such as REE and the heat producing elements Th and U are mainly retained in the residue or whether they will be concentrated in the melt phase. We are interested in how the composition of the crust varies through geological time as a function of different geothermal gradients and how partial melting processes at different P-T-H2O conditions influence the secular evolution of crust formation.