With this project, we perform research on the late Berriasian to early Valanginian time interval - a key interval of environmental change in the shallow-water platform succession of the northern Tethyan helvetic realm, during which a predominantly photozoan carbonate-producing community changed towards a heterozoan carbonate-producing community. This period is characterized by important paleoenvironmental and paleoceanographic change, which is amongst others expressed by a pronounced positive carbon isotope excursion. We analyze a representative selection of key sections in the helvetic realm, which are complemented with well-preserved sections in SE France, Italy and Poland. The sections are analyzed with regards to their mineralogy, facies and microfacies, sedimentology, sequence stratigraphy, geochemistry, and paleontology. The geochemical analyses consists in the analysis of stable carbon and oxygen isotope, redox-sensitive trace-metal concentrations, and phosphorus and organic-carbon contents”.