Abstract
The Triassic-Jurassic transition marks an important change in the basin configuration of the Greater Barents Sea. A contiguous basin with km-thick sedimentary successions changed into a partitioned basin with uplift in the west and foreland basins in the east with significant implication for the basin infill history. Our study employs a range of different high-resolution datasets from a distal part of the basin which unravels the complex pattern of differential uplift and erosion in the basin during this period.We record for the first time distinct angular unconformities between Upper Triassic strata and overlying Lower Jurassic strata within the basin, showing that large parts of it formed topographic highs. Our study links these angular unconformities to compression induced by the Novaya Zemlya Fold and Thrust Belt. A heterolithic basement below a thick sedimentary succession where the fold belt developed created a complex uplift pattern in the basin, at the same time similar to but different from typical forebulge areas. Compression caused inversion of older basement rooted faults defining platforms and graben systems throughout western parts of the Barents Sea basin, in addition to salt remobilization that resulted in differential uplift and erosion. These local zones of uplift controlled the sediment distribution pattern to the basin at a time when the most important reservoir units in the basin were deposited. This new understanding of the basin development explains hitherto enigmatic sequence boundaries that has inspired complex paleogeographic models in the past.
Highlights
The Upper Triassic to Lower Jurassic succession in the Norwegian sector of the Barents Sea basin (NBSB) is characterised by a pronounced transition from high rate of sedimentation and accommodation in the Triassic, to a condensed succession with limited accommodation, lower rates of sediment supply and bypass in the early Jurassic (Ryseth, 2014; Klausen et al, 2017)
Data coverage varies across the basin, we recognize that the two broad truncation trends mapped within the study area (Fig. 9) can be tentatively traced across the Greater Barents Sea: 1) a proximal uplift and erosion trend extends from northern parts of Norway, via the Fedynsky and Fersmanovskaya highs towards Kong Karls Land; and 2) a distal trend including the N-S striking truncation pattern of Fruholmen and Snadd formations with lower magnitude of uplift extending from the Hammerfest Basin towards Svalbard
This study shows for the first time the extent, magnitude and causal mechanism of a major late Triassic to early Jurassic compressional tectonic regime that affected the Norwegian Barents Sea
Summary
The Upper Triassic to Lower Jurassic succession in the Norwegian sector of the Barents Sea basin (NBSB) is characterised by a pronounced transition from high rate of sedimentation and accommodation in the Triassic, to a condensed succession with limited accommodation, lower rates of sediment supply and bypass in the early Jurassic (Ryseth, 2014; Klausen et al, 2017). In Ryseth (2014), the transition between the Triassic and Jurassic is thoroughly described, but differences in basin infill between the two periods are mainly attributed to hinterland rejuvenation in Fennoscandia, larger annual precipitation and reduced subsidence rates This change coincides with compression in stress regimes set up by the Novaya Zemlya Fold and Thrust Belt which culminated in the late Triassic to early Jurassic (Buiter and Torsvik, 2007; Ritzmann and Faleide, 2009; Faleide et al, 2018), created foreland basins such as the North and South Barents basins in the Russian sector (Scott et al, 2010; Suslova, 2013a, 2013b). It is beyond this study to present a full geodynamic model which explains the detailed impact of the Novaya Zemlya Fold and Thrust Belt on the Greater Barents Sea Basin, but the many important implications of our findings will likely stimulate further research on the topic and explain hitherto enigmatic stratigraphic relationships and salt reactivation across the basin
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
