It is only in the past decade that both vertical and horizontal crustal movements are finally accounted for when building models to understand the geodynamic evolution of our planet. Recent ground-breaking studies attempt to explain how mantle and plate tectonics concurred to modify Earth’s crust. However, this approach has not yet been applied to the Arctic realm, mainly because of the poor understanding of the ridges and basins in this remote region. The geological evolution in the Arctic is to a great extent influenced by tectonic events in neighbouring regions, in particular the North Atlantic and North Pacific oceans. The magmatic activity in the Arctic was very variable over time. In the Mesozoic, one of the largest submarine LIPs was formed along the Alpha-Mendeleev Ridge, while present day spreading along the ultra-slow Gakkel Ridge produces only very thin crust. These extreme variations point to highly variable mantle processes over time. Moreover, several episodes of Jurassic to recent subduction in the North Pacific, NE Asia and in the Arctic area itself generated slab graveyards that are imaged by improved tomographic models. However, a causal relationship has yet not been elucidated. Geoscientific information on the relationship between onshore and offshore geology and their relation to variations in the mantle are the key for a better understanding of the entire Arctic Ocean. This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics and aims to bring together a diversity of sub-disciplines including plate tectonic, mantle tomography, geodynamic modelling, igneous and structural geology, geophysical imaging, paleomagnetism, sedimentology and geochemistry. Particularly encouraged are papers that address lithospheric-mantle interactions in the North Atlantic, the Arctic and North Pacific regions, mantle dynamics as well as vertical and horizontal motion of crustal blocks.

Our invited contributors: Deborah R. Hutchinson (U.S. Geological Survey), Peter Japsen (Geological Survey of Denmark and Greenland, Denmark) and Andrew Schaeffer (Dublin Institute for Advanced Studies, Ireland) will present new and exciting results from the High Arctic region.