Tare Formation (Tareformasjonen)
(From NPD Bulletin no. 4)
From the Norwegian name for algae or sea tangle. The formation corresponds to the
informal Alstahaug formation or H5-2.
Well type section
(Statoil), coordinates 65°07'01.62"N, 07°42'42.61"E, from 1884 m to
1826 m (Fig. 36). No cores.
58 m in the type well.
Dark grey, green or brown claystones with some thin sandstone stringers show
a variable content of tuff.
The base is defined by an increase in tuff content. Consequently the sonic log
shows a decrease in interval transit time and an increase in density log
Lateral extent and variation
The Tare Formation is ubiquitous except near the crest of the Nordland Ridge.
The tuff content decreases southwards.
These sediments were deposited in a deep marine environment.
The Tare Formation is similar in both age and lithology to the Balder
Formation (Deegan & Scull, 1977) in the North Sea.