Horizontal movements in the eastern Barents Sea constrained by numerical models and plate reconstructions

Abstract

S U M M A R YThe eastern Barents Sea basins, west of Novaya Zemlya, were mildly inverted between Late Permian and Early Jurassic times, as indicated by mild folds in the basin sediments. Previous studies have suggested that the crustal part of Novaya Zemlya was thrust westward, but the magnitude of this compressive movement is not well known. Our aim is to provide an order-ofmagnitude constraint on the amount of shortening associated with the displacement of Novaya Zemlya and inversion of the eastern Barents Sea basins by combining numerical models and plate reconstructions in an iterative process. We use a 2-D finite-element method to model inversion of a pre-defined basin. The total amount of shortening imposed on the models is first constrained by plate reconstructions for the Barents Sea region for the Late Palaeozoic to Early Mesozoic. We assume that the shortening is caused by westward movement of the Siberian plate, but the magnitude of this westward displacement in plate reconstructions is highly uncertain due to the allochthonous nature of the rocks of Novaya Zemlya and the scarcity of palaeomagnetic data in the region. Our models show that shortening localizes in the model basin and at Novaya Zemlya and that westward propagation of deformation is more efficient when the strength of the lower crust is reduced. Part of the movement of the Siberian plate could be accommodated by thrusts at Novaya Zemlya and perhaps in the domain of the Kara Sea at the western margin of the Siberian plate. By comparing the inversion obtained in the numerical models to the inferred inversion structures in the eastern Barents Sea basins we further constrain the amount of shortening that caused the inversion and therewith improve the plate reconstructions for the region. Our models indicate that the westward movement of Novaya Zemlya occurred in the Late Triassic-Early Jurassic and was limited in magnitude to 100-200 km, which is considerably less than previous estimates (500-700 km).

Regional development and sequence stratigraphy of the Middle to Late Triassic Snadd Formation, Norwegian Barents Sea

“…documents this pronounced change in geometries of fluvial channels across the Intra-Carnian MFS and suggest that it could be linked to the Novaya Zemlya phase of the Uralide Orogeny. This westward protrusion of the hinterland fold and thrust belt has been modelled by Buiter and Torsvik (2007) to occur in the Late Triassic to Early Jurassic. Finally, the transgressive marine deposits of the Early Norian N1 are interpreted to mark the cessation of this progradation, and the gradual submersion of the C3 delta.…”

Triassic seismic sequence stratigraphy and paleogeography of the western Barents Sea area

“…The main southeastern source area was most likely related to the Uralian orogenic belt. However, local source areas cannot be ruled out, and Novaya Zemlya to the east may have played a more prominent role in Middle-Late Triassic (Buiter and Torsvik, 2007;Otto and Bailey, 1995;Petrov et al, 2008;Smelror et al, 2009;Torsvik and Andersen, 2002). As a consequence, the major basins in the east must have been filled in prior to major progradation into the Norwegian Barents Sea area in the late Induan.…”

“…Despite the various interpretations of the geological history, most authors agree that the eastern Barents Sea area was subjected to several phases of compression, associated with the formation of the Uralian Mountain Belt, uplift of Novaya Zemlya, and activity in the Taimyr Fold Belt (Buiter and Torsvik, 2007;Cocks and Torsvik, 2007;Golonka et al, 2003;Torsvik and Andersen, 2002). These crustal movements may have had some affects on formation of accommodation space and sediment supply in the western Barents Sea area.…”

Thermal‐mechanical modeling of salt‐based mountain belts with pre‐existing basement faults: Application to the Zagros fold and thrust belt, southwest Iran

“…In our experiments, we used a two‐dimensional, thermal‐mechanical finite element code (SOPALE) which can model high finite strain based on an Arbitrary Lagrangian Eulerian (ALE) method [ Fullsack , ]. This code has been extensively used in a range of different geodynamic modeling applications [ Pysklywec and Shahnas , ; Beaumont et al ., ; Pysklywec and Cruden , ; Cruden et al ., ; Buiter and Torsvik , ; Stockmal et al ., ; Beaumont et al ., ; Buiter et al ., ; Gray and Pysklywec , ; Nilfouroushan et al ., ].…”