The type section of the Vikingh�gda Formation: a new Lower Triassic unit in central and eastern Svalbard

Abstract

The Vikinghøgda Formation (250 m) is defined with a stratotype in Deltadalen‐Vikinghøgda in central Spitsbergen. The Vikinghøgda Formation replaces the Vardebukta and Sticky Keep Formations of Buchan et al. (1965) and the lower part of the Barentsøya Formation of Lock et al. (1978) as extended geographically by Mørk, Knarud et al. (1982) in central Spitsbergen, Barentsøya and Edgeøya. The formation consists of three member: the Deltadalen Member (composed of mudstones with sandstones and siltstones), the Lusitaniadalen Member (dominated by mudstones with thin siltstone beds and some limestone concretions) and the Vendomdalen Member (composed of dark shales with dolomite interbeds and nodules). The Lusitaniadalen and Vendomdalen members replace the former Sticky Keep Formation/ Member in the siirne areu. The Vikinghøda Formation can be followed through central and eastern Spitsbergen to Barentøya and Edgeøya and includes all sediments between the chert‐rich Kapp Starostin Formation (Permian) and the organic‐rich shales of the Botneheia Formation (Middle Triassic). The subdivision into three members is also reflected in the organic carbon content and palynofacies. Upwards. each succeeding member becomes more distal, organic‐rich and oil‐prone than the one below. The Vikinghøda Formation is well‐dated by six ammonoid zones. although the transitional beds between the Deltadalen and Lusitaniadalen members lack age diagnostic macrofossils. Corresponding palynozonation and magnetustratigraphy have also been determined. The overall stratigraphical development correlates well with other key Triassic areas in the Arctic, although intervals in the late Dienerian and early Smithian may be condensed or missing.

Biomagnetostratigraphy of the Vikinghogda Formation, Svalbard (Arctic Norway), and the geomagnetic polarity timescale for the Lower Triassic

“…DR1 [see footnote 1] and Figs. 6F and 6G in Mørk et al, 1999b). The parallel-laminated sandstone and siltstone beds are a prominent feature of the lower ~55 m of this member.…”

“…Palynology columns are: 2-Svalbard and Barents Sea region (Hochuli et al, 1989). 3-Vikinghøgda Formation (Fm) (Mørk et al, 1999b, and this work). 4-Bjørnøya (Mørk et al 1990).…”

“…The basal part of the Deltadalen Mb is sandstone resting on an erosional surface of partly silicifi ed siltstones of the Kapp Starostin Fm Mørk et al, 1999b). Above the basal sandstone, the Deltadalen Mb consists of silty shale with intervals dominated by siltstone or very fi ne-grained sandstones, often with hummocky cross-lamination.…”

“…2), where the Vikinghøgda Formation (Fm) is 250 m thick, and is divided into three members ( Fig. 1; Mørk et al, 1999b). The lowest, the Deltadalen Member (Mb) is exposed in the river banks in Deltadalen (the sampled section DR; Fig.…”

“…1). Within the central and eastern parts of the Svalbard archipelago, the Sassendalen Group is divisible into the Vikinghøgda and Botneheia formations (Mørk et al, 1999b), which span the Lower and Middle Triassic (Figs. 1 and 2).…”