Sverre Planke von der Universität Oslo wird am Montag, 03. Juni, 17:30 h (Geo-Hörsaal) im Rahmen des ECORD Distinguished Lecturer Programme einen Vortrag zu den Ergebnissen der IODP-Expedition 396 "Mid-Norwegian Margin Magmatism and Paleoclimate Implications" halten. Der Titel des Vortrags lautet "Drilling volcanic rifted margins to understand large igneous provinces and associated global warming". Alle sind herzlich eingeladen!

Continental breakup is a rare, but fundamental Earth event driven by massive internal forces. The splitting of Europe from Greenland some 56 million years ago was likely triggered by hot material rising from the deep mantle, forming a large igneous province. The breakup magmatism was associated with a global warming and extinction event, the Paleocene-Eocene Thermal Maximum (PETM). IODP Expedition 396 successfully drilled 20 holes on the mid-Norwegian continental margin to better understand continental breakup processes and to test the hypothesis that associated voluminous magmatism triggered the PETM. Hole locations were carefully selected on conventional and high-resolution 3D seismic data. In total, > 4 km of sediments and volcanic rocks were drilled, recovering 2 km of core.

The expedition recovered the first sub-basalt rocks on the Norwegian margin, documenting the presence of granite and inter-basalt sandstones on the Kolga High. We also cored three different seaward dipping reflectors (SDR) facies units on the Vøring Margin, representing basaltic lava flows emplaced in sub-aerial, coastal, and deep marine environments, respectively. An Outer High named Eldhø, was sampled at the termination of the Inner SDR and recovered spectacular pillow basalt units.

The PETM interval was cored at the Modgunn Arch and Mimir High holes. The Modgunn holes drilled into the upper part of a hydrothermal vent complex. High-resolution palynology and isotope geochemistry document that the hydrothermal venting took place near the start of the PETM, supporting the hypothesis that the global warming event was triggered by shallow-water eruption of greenhouse gases formed by heating of organic-rich sediments intruded by magmatic sills.

In conclusion, scientific drilling has provided essential data to document how the Earth’s internal processes have influenced the environment and life in deep time. To understand the environmental changes in the future, it is critical to keep on drilling the ocean basins to test new hypotheses and to discover our geological past.