Supplementary Files for: A multidisciplinary biostratigraphic framework for the Lower to Middle Miocene of the Norwegian North Sea – the siliceous succession of the Valhall–Hod area

A new multidisciplinary biostratigraphic framework, combining dinoflagellate cysts, microfossils, calcareous nannofossils, diatoms and silicoflagellates, is established for the Early to Middle Miocene deep marine clay and siliceous ooze in the southern Norwegian sector of the North Sea, based on core samples from the Valhall and Hod hydrocarbon fields. The framework was successfully tested on the equivalent chronostratigraphic level of several wells based on ditch cutting samples. New biostratigraphic events for the Danish and Norwegian North Sea resulting from this study are successfully used to correlate between the Valhall and Hod areas and supplement published zonation schemes. To our knowledge, this is the first time that diatoms and silicoflagellates from the fine fraction of microfossil samples have been used as correlation tools in the North Sea Basin. Dating of the siliceous/diatomite-rich interval results in a high-resolution (5–15 m intervals) biostratigraphic subdivision. The successful application of the new framework across the Valhall and Hod areas implies that it could also be useful in a more regional context. The new biostratigraphy enables the correlation of the lithostratigraphic units recently defined for the Danish offshore Neogene succession to the study area and the correlation of the sequence stratigraphic surfaces defined for the Danish sector to the southern Norwegian sector.