Rogn Formation (Rognformasjonen)
(Based on NPD Bulletin no. 4)
Viking Group
Name
The Norwegian word for spawn or hard roe. The formation corresponds to the
informally used Frøya formation.
Well type section
Well 6407/9-1
(Shell), coordinates 64°21'55.39"N, 07°47'21.76"E, from 1670 m to 1621 m
(Fig. 22). Three cores, recovery 35.5 m, including the base.
Thickness
49 m in the type well.
Lithology
The formation shows a coarsening upward sequence from siltstones and
shales to sandstones which constitute the bulk of the unit.
Basal Stratotype
The Rogn Formation is developed within the
Draupne Formation in the type
well. The lower boundary is defined at the base of a gradual decrease in
the gamma ray log and at a sharp decrease in interval transit time shown
by the sonic log (Fig. 21).
Lateral extent and variation
The formation is developed in the Draugen Field area, where it thins
laterally away from the type well.
Occurrences of formation tops in wells
Age
Oxfordian to Kimmeridgian.
Depositional environment
The formation's sandstones are interpreted as
shallow marine bar deposits.
Correlation
There are no known comparable units in surrounding areas.
