Thermotectonic Evolution of the Eurekan Belt in the Arctic Realm - The Influences of Transform Faults on Deformation and Exhumation

Intraplate strike-slip belts are key structures for understanding continental deformation; however, their thermotectonic evolution remains poorly understood. The Eurekan Belt, which extends for almost 2,000 km across Svalbard, North Greenland and the Canadian Arctic Archipelago, is a significant Cenozoic intracontinental orogen. The spatial and temporal deformation patterns of this intracontinental orogen and the controlling role of large transform faults are still unclear. This dissertation aims to reconstruct the thermal and tectonic evolution of the Eurekan Belt, focusing on how major faults influenced deformation, exhumation, topography and the opening of the Fram Strait.
Apatite fission track and (U–Th–Sm)/He thermochronology, zircon and apatite U–Pb dating, and petrographic observations were used to reconstruct the thermal evolution and assess fault-controlled exhumation across multiple segments of the Eurekan Belt.
The results reveal episodic, fault-related exhumation during the pre-Eurekan (66–60 Ma), Eurekan I (55–48 Ma), Eurekan II (44–38 Ma) and post-Eurekan (34–26 Ma) phases. Transform faults divided the crust into blocks with distinct thermal histories. Local increases in geothermal gradients, associated with basin formation and volcanism as well as thermal events along major transform faults, contributed to the thermal weakening of the crust, facilitating deformation. The contemporaneous activity of differently oriented fault systems produced heterogeneous topography, while post-Eurekan transtensional movements along the De Geer Fracture Zone contributed to crustal thinning and the opening of the proto-Fram Strait.
Overall, this dissertation provides a comprehensive overview of the thermotectonic evolution of a complex intracontinental orogen. It highlights the influence of long-lived faults and thermal processes on deformation patterns, topographic development and, potentially, regional climate during periods of major plate reorganization.