Tectonic and sedimentary structures in the northern Chukchi region, Arctic Ocean

The interpretation of tectonic and sedimentary structures in the northern Chukchi region, Arctic Ocean, is important to enhance our understanding of the tectonic evolution of this region. Therefore, multichannel seismic lines as well as seismic wide-angle reflection and refraction data were acquired in the northern Chukchi region during the RV Polarstern ARK-XXIII/3 summer expedition in 2008. These data have been processed and interpreted for the three main geological provinces (Chukchi Plateau, Chukchi Abyssal Plain, and Mendeleev Ridge) to describe the sedimentary and basement structures of the northern Chukchi region. Furthermore, using the age control of five exploration wells drilled near the coast of Alaska in combination with additional seismic reflection lines located on the Chukchi Shelf, we were able to date sediment horizons within the research area. In total, six sediment horizons with ages between Barremian/Hauterivian and the Top Miocene were identified. Especially, the Top Oligocene horizon forms a pronounce unconformity on the Chukchi Plateau and on the Mendeleev Ridge flanks. The origin of this unconformity can be associated with the opening of the Fram Strait indicating a significant change in the Arctic Ocean current system.