RESEARCH/REVIEW ARTICLE Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province Krzysztof Nejbert1, Krzysztof P. Krajewski2, Elz˙bieta Dubin´ ska1 & Zolta´ nPe´ cskay3 1 Institute of Geochemistry, Mineralogy and Petrology, University of Warsaw, Al. Z˙ wirki i Wigury 93, PL-02089 Warsaw, Poland 2 Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Warsaw, ul. Twarda 51/55, PL-00818 Warsaw, Poland 3 Institute of Nuclear Research, Hungarian Academy of Sciences, Bem te´ r 18/c, HU-4026 Debrecen, Hungary Keywords Abstract Dolerite; geochemistry; petrogenesis; KÁAr whole rock ages; Svalbard; Cretaceous. The dolerites of Svalbard are mineralogically and geochemically homogeneous with geochemical features typical of continental within-plate tholeiites. Their Correspondence geochemistry is similar to tholeiites belonging to a bimodal suite defined as the Krzysztof P. Krajewski, Institute of Geologi- High-Arctic Large Igneous Province (HALIP). KÁAr dating of numerous cal Sciences, Polish Academy of Sciences, dolerites sampled from many locations across Svalbard define a narrow time Research Centre in Warsaw, ul. Twarda 51/ span of this magmatism from 125.593.6 to 78.392.6 Mya. Discrete peaks of 55, PL-00818 Warsaw, Poland. E-mail:
[email protected] intensive activity occurred at 115.3, 100.8, 91.3 and 78.5 Mya corresponding to (1) breakup of the continental crust and formation of an initial rift as a result of mantle plume activity, located in the southern part of the Alpha Ridge; (2) magmatic activity related to spreading along the Alpha Ridge that led to the development of the initial oceanic crust and (3) continuation of spreading along the Alpha Ridge and termination of magmatic activity related to HALIP (last two peaks at 91.3 and 78.5 Mya).