home
previous page
NORLEX


Kyrre Formation (new) (Kyrreformasjonen)

(From NPD Bulletin no. 5)

Shetland Group

Name

Named after Olav "Kyrre" Haraldson, a Norwegian king (A.D. 1067-1093).

Well type section

Norwegian well 25/1-1 from 3582 to 2997 m, coordinates N 5953'17.40", E 0204'42.70" (Fig. 33). Part of one core (0.5 m), including the upper boundary.

Well reference sections

Norwegian well 35/3-2 from 2864 to 1665 m, coordinates N 6151105.98", E 0346'28.22" (Fig. 34). No cores.
Norwegian well 24/9-1 from 3638 to 3117 m, coordinates N 5916'09.48", E 0141'31.18" (Fig. 35). no cores.
Norwegian well 30/11-3 from 3162 to 2892 m, coordinates N 6002'38.59", E 023ri5.47" (Fig. 36). No cores.

Thickness

The formation is 585 m thick in the type well (25/1-1), 1199 m in well 35/3-2, 521 m in well 24/9-1 and 270 m in well 30/11-3.

Lithology

The formation consists of mudstones with occasional limestone beds. Some sandstone beds are found in parts of the Agat area. The mudstones are medium grey to grey, silty to calcareous, occasionally pyritic, glauconitic or micaceous. The sandstones are clear to white, and very fine to fine grained.

Basal stratotype

The lower boundary is defined by an increase in gamma-ray intensity and a decrease in velocity from the Tryggvason Formation into the Kyrre Formation (Fig. 33) due to changes in carbonate content. The boundary is unconformable on structural highs, usually above the Cromer Knoll Group.

Characteristics of the upper boundary

The upper boundary shows a decrease in gamma-ray intensity and an increase in velocity from the Kyrre Formation upwards into the Jorsalfare Formation (Figs. 33 and 34). This log change is also a result of the higher carbonate content and the presence of basal limestone beds in the Jorsalfare Formation.

Distribution

With the exception of the Gullfaks area, the formation is present in the Viking Graben, on the Tartipen Spur and the western margin of the Horda Platform.

Occurrences of formation tops in wells
Isochore map TRYGGVASON-KYRRE

Age

Late Turonian to Campanian.

Depositional environment

Open marine.

Remarks

The Kyrre Formation is time-equivalent with the Flounder Formation in the western part of the central North Sea and the upper part of the Hod Formation in the eastern part (Deegan & Scull 1977). It is also equivalent with the informal "formation D" of Deegan & Scull (1977) (Fig. 6).

home previous page