Evidence for Eurekan deformation within and around the Yermak Plateau, Arctic Ocean

The Yermak Plateau is a submarine plateau that lies to the north of Svalbard. Strong magnetic anomalies over its northeastern part led early interpretations of an origin by volcanic processes in an oceanic setting, during the formation of the SW Eurasia Basin and the Fram Strait between Svalbard and Greenland. However, subsequent geophysical research delivered evidence that at least the southern and northwestern parts of the plateau might be underlain by extended continental crust. This implies that plate reconstructions for times before the opening of the Eurasia Basin should account for these continental fragments. Up until now, the true northward extent of this microcontinent and neighbouring parts of Svalbard, and their late Cretaceous and Paleogene relative locations, have been incompletely known.

Moreover, during the late Cretaceous and Paleogene, large areas along the Northern Canadian and North Greenland continental margins, as well as the West Svalbard and Southwest Barents Sea continental margins were affected by compressional and strike-slip deformation that culminated in at least two discrete phases together referred to as the Eurekan orogeny, which dates from 53 to 34 Ma. Considering that the continental fragments of Yermak Plateau were located to the north of Greenland or even north of the Canadian Arctic Islands, it is conceivable that the Eurekan deformation might have also left traces within or around the present-day Yermak Plateau.

Here we report on evidence from seismic reflection data from the Sophia Basin, which separates the Yermak Plateau from Svalbard. Evidence for compressional and transpressional features beneath a Neogene-Quaternary sedimentary cover can be correlated to the two Eurekan deformation phases. Reconstructing the Yermak Plateau towards the North Greenland margin by closing the Neogene-Quaternary Lena Trough spreading system based on aeromagnetic data, we also found further evidence for continuity of geological structures between North Greenland and the northwestern Yermak Plateau.