Geochronological constraints on Caledonian strike-slip displacement in Svalbard, with implications for the evolution of the Arctic

The timing of Svalbard's assembly in relation to the mid-Paleozoic Caledonian collision between Baltica and Laurentia remains contentious. The Svalbard archipelago consists of three basement provinces bounded by N-S-trending strike-slip faults whose displacement histories are poorly understood. Here, we report microstructural and mineral chemistry data integrated with 40Ar/39Ar muscovite geochronology from the sinistral Vimsodden-Kosibapasset Shear Zone (VKSZ, southwest Svalbard) and explore its relationship to adjacent structures and regional deformation within the circum-Arctic. Our results indicate that strike-slip displacement along the VKSZ occurred in late Silurian-Early Devonian and was contemporaneous with the beginning of the main phase of continental collision in Greenland and Scandinavia and the onset of syn-orogenic sedimentation in Silurian-Devonian fault-controlled basins in northern Svalbard. These new-age constraints highlight possible links between escape tectonics in the Caledonian orogen and mid-Paleozoic terrane transfer across the northern margin of Laurentia.