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Geoscience seminar - Jennifer Galloway, Geological Survey of Canada

Environmental effects of the High Arctic Large Igneous Province: Land and Marine Impact

12.11.2019 | Susanne Weis Fogh

Dato ons 13 nov
Tid 14:15 15:00
Sted Geoscience Auditorium, building 1671-137

Large Igneous Provinces (LIPs) may affect global climate and environments through interaction with volatile-rich host rocks encountered during emplacement through release of substantial quantities of CO2, SO2, CH4, Hg, and trace metals. LIP volcanism is implicated in almost every mass extinction during Earth’s history, often with contemporaneous rapid climatic change. The High Arctic Large Igneous Province (HALIP) is probably the least studied LIP in the world. It was widespread with exposed igneous components on Svalbard, Franz Josef Island, New Siberian Islands, and Axel, Ellesmere, and Ellef Ringnes islands in the Sverdrup Basin of Arctic Canada. However, the volume of material is poorly constrained and thought to be about ¼ the volume of the much larger Paraná-Etendeka LIP that is implicated in global carbon cycle perturbations and climate change during the Early Cretaceous. However, the size of a LIP does not appear to be as important as the composition of the host-rocks it encounters in causing environmental crises. 

In the Sverdrup Basin of Canada, four main cycles of the HALIP are recognized: Valanginian-early Barremian; Barremian/late Hauterivian–Aptian basalts of the Paterson Island and Walker Island members of the Isachsen Formation; late Aptian-Cenomanian continental flood basalts of the Strand Fiord Formation; and, late Cenomanian-Maastrichtian Hansen Point volcanics. Cycles 1-3 comprise the main tholeiitic phase of magmatism between ca. 130-90 Ma. From the Late Jurassic to Late Cretaceous, multiple climatic and environmental events are documented in the Sverdrup Basin. These include

  1. an interval of carbon perturbation in the Volgian (late Tithonian) that precedes the oldest known age of the HALIP in Canada
  2. a relatively cool and moist late Valanginian climate episode contemporaneous with a positive carbon isotope excursion in marine rocks
  3. an interval of warming in the Hauterivian
  4. multiple cold snaps in the late Aptian and Albian
  5. intervals of ocean anoxia.

This talk will explore the putative role of the HALIP in affecting climate and environmental change through various processes during its episodic emplacement in polar regions.

Seminar, Institut for Geoscience