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SSF-Svalbard Science Forum

Cenozoic magmatic-hydrothermal activity in northern Spitsbergen, with implications for offshore hydrothermal mineral systems (RiS-11825)

Tildelt: kr 99 999

The geologic evolution of the High Arctic during the Cenozoic is critical for our understanding of continental breakup mechanisms and opening of marine ‘gateways’. These processes control exchange of deep-water between the world’s oceans and therefore influence climate patterns. Opening of the Fram Strait between Greenland and Spitsbergen started ca. 15 million years ago and the region provides a natural laboratory to investigate geologic processes at a continent–ocean transition. During recent years, volcanic products and their source rocks from mid-ocean ridge segments of the Lena Trough have been analysed for their isotopic compositions suggesting that geochemically enriched signatures potentially reflect remnants of old continental lithosphere beneath Fram Strait. This suggests that continent–ocean transitions are structurally more complex than generally assumed. Enigmatic volcanic centres, ca. 1 Ma old, occur in NW Spitsbergen, and they have been interpreted as expressions of ‘oceanic’ volcanism on rifted continental lithosphere. To the best of our knowledge, no modern geochemical datasets exist for these basaltic rocks from Spitsbergen, including the ca. 10 Ma old flood basalts, which hampers development of an integrated tectonomagmatic model for the opening of Fram Strait, a tangible example of how continental breakup may influence climate patterns. This project aims to collect samples from the Quaternary volcanic centres and Miocene flood basalts in NW Spitsbergen for a modern petrological (e.g., pressure–temperature of melt origin) and isotopic study (e.g., 176Hf/177Hf, 187Os/188Os, 3He/4He, 34S/32S) to constrain the causes and sources of this young magmatic activity. The results will allow to further improve our understanding of the Cenozoic evolution of the High Arctic and its marine magmatic-hydrothermal mineral systems, which are currently being investigated by various Norwegian organisations as future sources of metals for a ‘green’ economy.

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SSF-Svalbard Science Forum