The Upper Carboniferous Hyrnefjellet Formation on Svalbard: An update on the depositional evolution

The Hyrnefjellet Formation contains the oldest sediments in the Inner Hornsund Trough on Spitsbergen, the largest island of the Svalbard archipelago. The Formation has last been studied in detail during the 1960's and 80's. The Inner Hornsund Trough is one of five Upper Carboniferous rift basins on Svalbard. The onset of rifting of the Upper Carboniferous rift basins coincides with a climatic shift from humid to arid and a regional transgression. The Hyrnefjellet Formation consists of upward coarsening cycles of red mud- and sandstones and conglomerates deposited in a terrestrial alluvial fan setting and grades upwards into the carbonate dominated Treskelodden Formation. In this study we have combined classical sedimentological fieldwork with airborne photogrammetry to investigate the depositional evolution of the Hyrnefjellet Formation. From stratigraphic logging as well as digital outcrop models we were able to identify several syn-sedimentary faults within the Hyrnefjellet Formation.