PUBLICATIONS Geochemistry, Geophysics, Geosystems RESEARCH ARTICLE Origin and evolution of the Kolbeinsey Ridge and Iceland 10.1002/2014GC005540 Plateau, N-Atlantic Key Points: Bryndıs Brandsdottir 1, Emilie E. E. Hooft2, Rolf Mjelde3, and Yoshio Murai4 The 700 km KRISE profile shows crustal structure between the KR and 1Institute of Earth Sciences, Science Institute, University of Iceland, Reykjavık, Iceland, 2Department of Geological Sciences, Aegir Ridges University of Oregon, Eugene, Oregon, USA, 3Department of Earth Science, University of Bergen, Bergen, Norway, 4Institute Extinct spreading centers coexisted with the extinct AEgir Ridge for Seismology and Volcanology, Hokkaido University, Sapporo, Japan We constrain spreading history from the opening of the N-Atlantic to present Abstract Variations in crustal structure along the 700 km long KRISE7 refraction/reflection and gravity profile, straddling 66.5N across the Iceland Shelf, Iceland Plateau and western Norway Basin confirm that Correspondence to: extinct spreading centers coexisted with the now extinct Ægir Ridge prior to the initiation of the Kolbeinsey B. Brandsdottir, Ridge at 26 Ma. The western 300 km of the profile, across the Iceland shelf, formed by rifting at the Kolbein-
[email protected] sey Ridge, whereas the eastern 400 km, across the Iceland Plateau and the western Norway Basin, formed by earlier rifting, possibly containing slivers of older oceanic or continental crust rifted off the central E- Citation: Brandsdottir,B.,E.E.E.Hooft,R.Mjelde, Greenland margin along with the Jan Mayen Ridge. Crustal thickness increases gradually across the Iceland and Y. Murai (2015), Origin and evolution shelf, from 12 to 13 km near the Kolbeinsey Ridge to 24–28 km near the eastern shelf edge, decreasing of the Kolbeinsey Ridge and Iceland abruptly across the shelf edge, to 12–13 km.