Abstract. The Svalbard Archipelago consists of three basement terranes that record a
complex Neoproterozoic–Phanerozoic tectonic history, including four
contractional events (Grenvillian, Caledonian, Ellesmerian, and Eurekan) and
two episodes of collapse- to rift-related extension (Devonian–Carboniferous
and late Cenozoic). Previous studies suggest that these three terranes likely
accreted during the early to mid-Paleozoic Caledonian and Ellesmerian
orogenies. Yet recent geochronological analyses show that the northwestern
and southwestern terranes of Svalbard both record an episode of amphibolite
(–eclogite) facies metamorphism in the latest Neoproterozoic, which may
relate to the 650–550 Ma Timanian Orogeny identified in northwestern
Russia, northern Norway, and the Russian Barents Sea. However, discrete
Timanian structures have yet to be identified in Svalbard and the Norwegian
Barents Sea. Through analysis of seismic reflection, as well as regional
gravimetric and magnetic data, this study demonstrates the presence of
continuous thrust
systems that are several kilometers thick, NNE-dipping, deeply buried, and extend thousands of kilometers from northwestern Russia to
northeastern Norway, the northern Norwegian Barents Sea, and the Svalbard
Archipelago. The consistency in orientation and geometry, as well as apparent
linkage between these thrust systems and those recognized as part of the
Timanian Orogeny in northwestern Russia and Novaya Zemlya, suggests that the
mapped structures are likely Timanian. If correct, these findings would
imply that Svalbard's three basement terranes and the Barents Sea were
accreted onto northern Norway during the Timanian Orogeny and should hence
be attached to Baltica and northwestern Russia in future
Neoproterozoic–early Paleozoic plate tectonics reconstructions. In the
Phanerozoic, the study suggests that the interpreted Timanian thrust systems
represent major preexisting zones of weakness that were reactivated,
folded, and overprinted by (i.e., controlled the formation of new) brittle
faults during later tectonic events. These faults are still active at
present and can be linked to folding and offset of the seafloor.
Crestal fault geometries reveal late halokinesis and collapse of the Samson Dome, Northern Norway: Implications for petroleum systems in the Barents Sea
