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A new Lower Cretceous lithostratigraphic unit of the Western Barents Shelf, named the Klippfisk Formation, is formally introduced. The formation represents a condensed carbonate succession deposited on platform areas and structural highs, where it consists of limestones and marls, often glauconitic. The limestones may have a nodular appearance, and fossil debris, which are dominated by Inoceramus prisms, may be abundant. The Klippfisk Formation is composed of two members: the Kutling Member defined herein from cores drilled on the Bjarmeland Platform, and the coeval Tordenskjoldberget Member described on Kong Karls Land. The base of the formation is defined by the abrupt decrease in gamma‐ray intensity, where the dark shales of the underlying Hekkingen or Agardhfjellet formations are replaced by marls. It is often unconformable. The Klippfisk Formation is of Berriasian to Early Barremian age and appears to be time‐transgressive over parts of the Western Barents Shelf (including Kong Karls Land). It passes laterally into the basinal Knurr Formation. On Kongsøya (Kong Karls Land) a thin shale unit, bounded by unconformities, earlier included in the Tordenskjoldberget Member, represents the northernmost extension of the overlying Kolje Formation in the Barents Shelf.

The Longyearbyen CO 2 storage project drilling and coring campaign in central Spitsbergen provided new insights on the shale-dominated Middle Jurassic to Lower Cretaceous Agardhfjellet Formation, which is the onshore counterpart to the Fuglen Formation and the prolific source rocks of the Hekkingen Formation in the Barents Sea. Logs of magnetic susceptibility, organic carbon content, organic carbon isotopes and XRF geochemistry on the cores, together with wireline logs, biostratigraphy and sedimentology, have made it possible to refine the interpretation of the depositional environment and to identify transgressive-regressive (TR) sequences. Several key sequence-stratigraphic surfaces are identified and suggested to be correlative in Central Svalbard, and four of them, although not necessarily chronostratigraphic, also to surfaces in the Barents Sea. Due to the nearly flat-lying thrust faults in the upper décollement zone of the West Spitsbergen Fold and Thrust Belt, there is some concern about the lateral correlation of the sequences within Spitsbergen. However, some of the TR sequence surfaces appear to be of regional importance and are recognised both onshore Svalbard and offshore on the Barents Shelf. The observations suggest a shallow-marine shelf depositional environment within an epicontinental sea with variable dysoxic, anoxic and oxic sea-floor conditions. The majority of the facies vary from outer shelf to transition zone or prodelta and lower shoreface/distal delta front. In one outcrop, proximal facies, i.e., delta front or middle shoreface, are recognised. In our study area the nearly 250 m-thick, fine-grained Agardhfjellet Formation is proposed to represent distal shoreline clinoforms and a precursor to the overlying forward-and southward-stepping wedge of the Valanginian Rurikfjellet Formation and the Barremian to Early Aptian Helvetiafjellet Formation.

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A revised formal lithostratigraphy for the Mesozoic-Cenozoic succession of the onshore

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