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Original Article |
1 Department of Earth Science, University of Bergen, Allegt. 41, 5007 Bergen, Norway (e-mail: Rolf.Mjelde{at}geo.uib.no)
2 Department of Geosciences, University of Oslo, PO Box 1047, Blindern, 0316 Oslo, Norway
3 Department of Earth Science, University of Bergen, Allegt. 41, 5007 Bergen, Norway
4 SOEST, Department of Geology and Geophysics, University of Hawaii, 1680 East–West Road, Honolulu, HI 96822, USA
The primary aim of the present paper is (1) to review the tectonomagmatic evolution of the North Atlantic, and (2) constrain evolutionary models with new lithosphere strength estimates and interpretation of potential field data north of Iceland. Our interpretations suggest that the breakup along the entire eastern Jan Mayen Ridge occurred at c. 55 Ma. Calculations of lithospheric yield strength indicate that the continental rifting in East Greenland, which led to oceanic crustal formation west of the Jan Mayen Ridge at c. 25 Ma, could have started at c. 42.5 Ma. Symmetrical V-shaped gravimetric ridges, which can be traced back to c. 48 Ma, document large-scale asthenospheric flow both north and south of Iceland. Such flow is predicted by geodynamic models of mantle plumes, but has yet to be predicted by other mechanisms. The results from the compartments north of Iceland, viewed in a regional context, strengthen the hypothesis attributing the anomalous magmatism in the North Atlantic area from c. 70 Ma to the present to the Icelandic plume.
