Tare Formation (Tareformasjonen)
(From NPD Bulletin no. 4)
Rogaland Group
Name
From the Norwegian name for algae or sea tangle. The formation corresponds to the
informal Alstahaug formation or H5-2.
Well type section
Well 6507/12-1
(Statoil), coordinates 65°07'01.62"N, 07°42'42.61"E, from 1884 m to
1826 m (Fig. 36). No cores.
Thickness
58 m in the type well.
Lithology
Dark grey, green or brown claystones with some thin sandstone stringers show
a variable content of tuff.
Basal Stratotype
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
readings.
Lateral extent and variation
The Tare Formation is ubiquitous except near the crest of the Nordland Ridge.
The tuff content decreases southwards.
Occurrences of formation tops in wells
Isochore map TANG-TARE
Age
Late Paleocene.
Depositional environment
These sediments were deposited in a deep marine environment.
Correlation
The Tare Formation is similar in both age and lithology to the Balder
Formation (Deegan & Scull, 1977) in the North Sea.
