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

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 num...

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Bibliographic Details
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
geo
archeo
Alpha Ridge
Arctic
Barents Sea
alpha ridge
Polar Research
Online Access:https://doi.org/10.3402/polar.v30i0.7306
https://doaj.org/article/59c7503bfa9b494dbf27a9dd4ba8c171
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Summary: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).

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