Understanding processes and events that formed the Canadian Polar Margin
Final Report Abstract
This project was dealing with the Eocene morphotectonic evolution of Pearya, a terrane situated along the northernmost margin of North America. We found that Pearya has experienced pronounced and episodic exhumation during the Eurekan intraplate orogeny. Exhumation patterns of the Eurekan Belt in Pearya are similar to those of Svalbard, and also coincide with stalled subsidence of the Lomonosov Ridge, but are different from those of southern Ellesmere Island. Timing of exhumation seems to be controlled by changes in spreading rates and directions of the Norwegian-Greenland Sea, confirming assumptions that intraplate deformation results from far-field effects of processes along the plate margins. Exhumation patterns vary across the Eurekan belt, controlled by structures inherited from previous orogenies. We further showed that the main period of high-latitude topography formation coincided with suggested periods of continental glaciation and occurrence of ice-rafted debris in Eocene and Oligocene offshore sediments, implying that the Eurekan Orogen may have formed the nucleus for ice caps and glaciation. Our data also reflect the youngest erosion history: During the last 5 Ma, Pearya has experienced pronounced glacial erosion and incision, which was locally sufficiently intense to partially reset the apatite (U-Th)/He system, even in the absence of obvious tectonic activity. Intense glacial erosion occurred independent from lithologies, but is always associated with certain landforms, namely sidewalls of glacially-carved valleys.
Publications
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Proterozoic to Cretaceous evolution of the western and central Pearya Terrane (Canadian High Arctic). Journal of Geodynamics, 120, 45-76.
Estrada, Solveig; Mende, Katja; Gerdes, Axel; Gärtner, Andreas; Hofmann, Mandy; Spiegel, Cornelia; Damaske, Detlef & Koglin, Nikola
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Exhuming the Top End of North America: Episodic Evolution of the Eurekan Belt and Its Potential Relationships to North Atlantic Plate Tectonics and Arctic Climate Change. Tectonics, 38(12), 4207-4228.
Vamvaka, Agni; Pross, Jörg; Monien, Patrick; Piepjohn, Karsten; Estrada, Solveig; Lisker, Frank & Spiegel, Cornelia
