Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

• Published in: Polar Research
• Main Authors: Zoltán Pécskay, Elzbieta Dubinska, Krzysztof P. Krajewski, Krzysztof Nejbert
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2011
• Subjects: Dolerite; geochemistry; petrogenesis; K–Ar whole rock ages; Svalbard; Cretaceous; Environmental sciences; GE1-350; Oceanography; GC1-1581; Alpha Ridge; Arctic; Barents Sea; alpha ridge; Polar Research
• Online Access: https://doi.org/10.3402/polar.v30i0.7306; https://doaj.org/article/59c7503bfa9b494dbf27a9dd4ba8c171

The dolerites of Svalbard are mineralogically and geochemically homogeneous with geochemical features typical of continental within-plate tholeiites. Their geochemistry is similar to tholeiites belonging to a bimodal suite defined as the High-Arctic Large Igneous Province (HALIP). K–Ar dating of numerous dolerites sampled from many locations across Svalbard define a narrow time span of this magmatism from 125.5±3.6 to 78.3±2.6 Mya. Discrete peaks of 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).