Båt Group (Båtgruppen)

(From NPD Bulletin no. 4)


Norwegian name for boat. The Båt Group comprises the lower and middle parts of the earlier used informal Halten group (HI).

Type area

The transition from the Halten Terrace to the Trøndelag Platform in Blocks 6507/11 and 6507/12. The group's development is illustrated by the type section of its basal unit in well 6507/12-1 (Saga Petroleum), coordinates 65°07'01.62"N, 07°42'42.61"E from 2920 m to 2213 m (Fig. 7), and in the reference well 6407/1-2 (Statoil), coordinates 64°47'50.61"N, 07°02'23.76"E from 4548 m to 3907 m (Fig. 8).


707 m in well 6507/12-1 and 641 m in well 6407/1-2.


The Båt Group consists of alternating sandstone and shale/siltstone units, with sandstone as the dominant lithology.

Basal Stratotype

The base of the Båt Group is defined by the base of the Åre Formation as described herein.

Lateral extent and variation

The Båt Group is present in most of the wells drilled to date on Haltenbanken and Træna-banken, with maximum thicknesses in excess of 700 m. The upper part of the succession is progressively truncated towards the crestal part of the Nordland Ridge and the whole group is absent on the highest parts of the ridge. Shallow boreholes off the Trøndelag coast (Bugge et al. 1984) indicate that the Åre Formation may be absent and younger strata within the Båt Group onlap directly on Pre-cambrian basement.


Rhaetian to Toarcian.

Depositional environment

Shallow marine to deltaic environments dominated during deposition of the group.


The group corresponds to the mid-Fruholmen to mid-Stø Formation sequence in the Realgrunnen Group of the Hammerfest Basin. The group is also partially equivalent to the Statfjord Formation and the Dunlin Group of the North Sea.


The group comprises four formations (Overview-Jurassic) all of which are defined herein:

Åre Formation
Tilje Formation
Tofte Formation
Ror Formation

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