Gapeflyndre Member [new]

updated to follow: Stratigraphic Guide to the Cromer Knoll, Shetland and Chalk Groups of the North Sea and Norwegian Sea. Felix M. Gradstein & Colin C. Waters (editors), Mike Charnock, Dirk Munsterman,  Michelle Hollerbach, Harald Brunstad, Øyvind Hammer & Luis Vergara (contributors). Newsletter on Stratigraphy, vol 49/1 pp71-280, 2016

Shetland Group, Blålange Formation


Derivatio nominis: Norwegian for the American plaice or sole, Hippoglossoides platessoides. Appropriately, this fish is found on soft bottoms, most often in water depths of 90-250m in the North Atlantic region including the Norwegian Sea.

Informal name: Lange sandstones.


Interbedded sandstones, siltstones and mudstones. The sandstones frequently contain glauconite or kaolinite. Not cored in the type well.


The gross thickness of the member is 221.5 m in the type well.

Geographical distribution

This member is attributed to the Blålange Formation (Shetland Group) and found in the Slørebotn Sub-basin, on the eastern Møre margin.

Type well

Well name: 6305/12-1

WGS84 coordinates: N 63°1'25.73", E 05°47'23.94"
UTM coordinates: 6991476.94 N 641178.97 E
UTM zone: 31
Drilling operator name: Norsk Hydro Produksjon AS
Completion date: 18.09.1991
Status: P & A
Interval of type section (m) & thickness in type well: 3451.5 m - 3230 m, 221.5 m thickness.

Reference wells

None designated.

Well log characteristics

The member shows an irregular and serrate GR log profile and a series of cleaning-upward profiles that probably represent repeated sandstone input.

Upper and lower boundaries

Upper boundary

The upper boundary is more difficult to define due to the progressive decrease in the frequency of sandstone interbeds.

Lower boundary

The lower boundary of the Gapeflyndre Member is characterised by negative separation between density and neutron porosity logs defining the development of sandstones above a predominantly mudstone interval and is well defined on both gamma ray and sonic logs.


Late Cretaceous, Cenomanian.

Depositional environment

Deep marine.

Core is lacking but based on log character and location within the Slørebotn sub-basin, the member is considered to be a series of interbedded basin mudstones/mud-dominated turbidites and lobe fringe or interlobe overbank turbidite sandstones.


A possible 'Blodøks Formation Equivalent' was noted by the Operator in the type well 6305/12-1 above this member between 3140m-3158mMD. An equivalent of the Gapeflyndre Member is recognized in the 6205/3-1 R well (2925m-2973m). This well is located in a more basinal position and the lithology dominated by siltstones.