The Barents Shelf, stretching from the Arctic Ocean to the coasts of northern Norway and Russia, and from the Norwegian–Greenland Sea to Novaya Zemlya, covers two major geological provinces. This review concentrates on the western province, with its complex mosaic of basins and platforms. A growing net of coverage by seismic data, almost 70 deep hydrocarbon exploration wells and a series of shallow coring programmes, have contributed greatly to our understanding of this province, supplementing information from neighbouring land areas. The late Paleozoic to present-day development of the region can be described in terms of five major depositional phases. These partly reflect the continuing northwards movement of this segment of the Eurasian plate from the equatorial zone in the mid-Devonian–early Carboniferous up to its present-day High Arctic latitudes, resulting in significant climatic changes through time. Important controls on sedimentation have involved varying tectonic processes along the eastern, northern and western margins of the shelf, whereas short- and long-term local and regional sea-level variations have further determined the depositional history of the province.

https://www.tandfonline.com/doi/pdf/10.1111/j.1751-8369.2008.00085.x

The post-Caledonian development of Svalbard and the western Barents Sea

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

Palaeogeographic and tectono-stratigraphic considerations in the greater Barents Sea show that the distribution of reservoirs and hydrocarbon source rocks from the Late Palaeozoic to the Palaeogene can be related to three tectonic phases. Firstly, the Palaeozoic Caledonain Orogeny caused uplift to the west, followed by eastward sediment distribution across the shelf, towards carbonate platforms to the east. Secondly the Late Palaeozoic–Mesozoic Uralide Orogeny induced uplift to the east, causing widespread clastic deposition and reversal of the sediment distribution pattern. Thirdly, major Late Mesozoic–Cenozoic rifting and crustal breakup in the western Barents Sea led to the current basin configuration. Reservoir rocks comprise Late Palaeozoic carbonates and spiculites, Mesozoic terrestrial and marine sandstones and Palaeogene deep-water sandstones. Hydrocarbon source rocks range in age from Silurian to Early Cretaceous, and are grouped into three petroleum systems derived from Late Palaeozoic, Triassic and Late Jurassic source rocks. Multiple tectonic episodes caused formation of a variety of trap types, of which extensional fault blocks and gently folded domes have been the most prospective. Volumetric considerations of generated petroleum indicate that charging is not a limiting factor, except in the western margin.

Chapter 10 Tectonostratigraphy of the greater Barents Sea: implications for petroleum systems

The interpretation of an unpublished data set of shallow stratigraphic cores and deep, seismic profiles from the northern Barents Shelf has provided new information about the Middle and Late Triassic development of the Barents Shelf and Svalbard. At that time, sediment sources along the eastern and south-eastern margins of the Barents Sea controlled the infilling of a previously deeper shelf area, gradually converting it into a paralic platform. Compared with the eastern source, sediment volumes from other areas were small. In our data, there are no indications of a provenance area north of Svalbard. Progradation from the ESE resulted in diachronous lithostratigraphic boundaries. The organic-rich shales of the Botneheia and Steinkobbe formations were deposited in the remaining deeper shelf areas in the western and north-western Barents Sea shelf, from the Olenekian to the latest Ladinian, by which time the progradation from the ESE had reached eastern Svalbard. In mid-Carnian times, the area of paralic deposits extended from the eastern Barents Sea into the Svalbard Archipelago.

https://www.tandfonline.com/doi/pdf/10.1111/j.1751-8369.2008.00086.x

Evolution of the Triassic shelf in the northern Barents Sea region

Seismic character of bottom simulating reflectors: examples from the mid-Norwegian margin

Triassic sandstones from a large area ranging from the Pechora Sea and Novaya Zemlya in the southeast to the western Barents Sea and Svalbard have been analyzed by petrographic, mineralogical, mineral-chemical, and Sm-Nd bulk-rock isotopic methods. The largest compositional variation is seen in the Lower Triassic deposits. Epidote-bearing, lithic-rich sandstones are characteristic of the eastern Barents Sea, Novaya Zemlya, and the Timan-Pechora Basin, and indicate a provenance from the Polar Urals. Quartzo-feldspathic sandstones in the Hammerfest Basin may have been derived from deeper crustal plutonic and metamorphic rocks of the Caledonides and Baltic margin, whereas the source of quartz-dominated sandstones on Spitsbergen was a paleoland in the northwest, in the vicinity of paleo-Greenland. Calculated Sm-Nd provenance ages for Lower Triassic deposits are in the range of 1500-1880 Ma for sandstones from Spitsbergen, the Hammerfest Basin, and the Finnmark Platform. Sandstone provenance ages for samples analyzed from the eastern Barents Sea are significantly younger, with a range of 600-1280 Ma and an average of 780 Ma. Sandstones in central shelf areas, i.e., the Nordkapp Basin-Bjarmeland Platform, are rich in both lithics and feldspar and have intermediate provenance ages (960-1630 Ma). The largest influence of older components occurs in samples from the Nordkapp Basin. This may be related to sediment supply both from the Caledonized Baltic margin and Uralides, and from local uplifted areas composed of Paleozoic sedimentary rocks. Middle and Upper Triassic sandstones display compositional variations at different times in different areas due to local changes in provenance. However, in the Upper Triassic there appears to be a convergence in sandstone compositions reflecting both more extensive mixing of components from the eastern and western provenance areas as well as changes to more evolved compositions of the erosional products derived from the paleo-Urals. There is also a question of increasing influence from possible paleolands in the northeast. The most important compositional change was the distinct increase in sandstone maturity that took place on a regional scale in the Arctic in the latest Triassic-Early Jurassic. This may in part have been caused by extensive reworking connected with a regional transgression and sea-level raise.

Compositional Variations and Provenance of Triassic Sandstones from the Barents Shelf

Application of sequence stratigraphic principles, detailed facies analyses, mineralogy, organic geochemistry and high-resolution biostratigraphic correlations to continuously cored units from the Middle Jurassic-Lower Cretaceous succession of the Troms III and Nordland VII areas provide new information on the sedimentary history offshore northern Norway. Two new lithostratigraphical units, the Masnykan Formation and Rauate Member, are formally described. In the Troms III area, the lowermost sequence boundary of late Bajocian-early Bathonian age occurs in the upper part of the Sto Formation, while at Andoya and in the Nordland VII area it occurs on top of weathered basement. The Bathonian to Oxfordian succession is dominated by the transgressive systems tracts formed by the proximal sandstones of the Masnykan (new unit in the Nordland VII area) and Ramsa (Andoya) formations which distally grade into the Fuglen Formation in the offshore Troms area. The Hekkingen Formation occurs in all areas above the late Oxfordian sequence boundary. In the Nordland VII area, siltstones of the Rauate Member (new) represent the most proximal deposits of the Hekkingen Formation. Basinward the Rauate Member grades into the very organic-rich claystone of the Alge Member. We explain the deposition of the Alge Member by a modified "expanding puddle" model. Overlying the Alge Member a thick (Volgian-Berriasian), highstand systems tract forms the dark claystones and siltstones of the Krill Member in all areas. Sediments reflecting tectonic activity in the earliest Cretaceous are overlain by a regional early Valanginian sequence boundary that marks a clear shift in sedimentary regime. Slow sedimentation rate and high bioclastic input resulted in deposition of a condensed marly succession on shallow shelf areas (Klippfisk and Nybrua formations). The late Hauterivian-earliest Barremian sequence boundary is followed by renewed marine dark claystone deposits (Kolje Formation). The change in depositional regime across the condensed unit is associated with mineralogy changes of the claystones, which suggest increased influence from erosion of feldspar-rich rocks towards the end of this period.

Middle jurassic-lower cretaceous transgressive-regressive sequences and facies distribution off northern nordland and troms, Norway

Magnetic susceptibility of Mesozoic and Cenozoic sediments off Mid Norway and the role of siderite: implications for interpretation of high-resolution aeromagnetic anomalies

Mai Britt E. Mørk

Papers

Compositional Variations and Provenance of Triassic Sandstones from the Barents Shelf

Middle jurassic-lower cretaceous transgressive-regressive sequences and facies distribution off northern nordland and troms, Norway

Magnetic susceptibility of Mesozoic and Cenozoic sediments off Mid Norway and the role of siderite: implications for interpretation of high-resolution aeromagnetic anomalies

Origin of carbonate-cemented beds on the Naglfar Dome, Vøring Basin, Norwegian Sea