Middle Miocene magmatic activity in the Sophia Basin, Arctic Ocean – evidence from dredged basalt at the flanks of Mosby Seamount

• Main Authors: Geissler, Wolfram, Estrada, Solveig, Riefstahl, Florian, O'Connor, John, Spiegel, Cornelia, Van den Boogard, Paul, Klügel, Andreas
• Format: Conference Object
• Language: unknown
• Published: 2017
• Subjects: Arctic; Arctic Ocean; Fram Strait; Svalbard; Yermak plateau
• Online Access: https://epic.awi.de/id/eprint/45003/; https://hdl.handle.net/10013/epic.51664

The area to the northwest of Svalbard was affected by repeated tectono-magmatic processes starting from the Cretaceous formation of the High Arctic Large Igneous Province, to Late Cretaceous/early Cenozoic birth of the Eurasian Basin towards the establishment of a full seafloor-spreading regime along the Lena Trough/Fram Strait in Middle Miocene. These processes also affected the Sophia Basin located in-between the Yermak Plateau and the northern Svalbard Shelf. In 2013 a little piece of basalt could be dredged from the southern flank of the Mosby Seamount, the central landmark within the Sophia Basin. Geochemical analyses support our assumption that the rock fragment has a local origin and that it was not rafted towards the sample site by ice. The trace element composition implies that the basalt had incorporated marine sediments and also Fe-Mn crusts or nodules. According to geochronological data the basalt erupted ~13 Ma, contemporaneous to incipient seafloor spreading in the nearby Lena Trough and volcanic activity in northern Svalbard. Assuming a link of the dredged basalt with seismic indication of sediment covered lava flows and sill intrusion around Mosby Seamount, its middle Miocene age can be used to better constrain the regional seismo-stratigraphy.