Alke Formation (new)

(See also NPD Bulletin no. 3 for older definitions)

Hegre Group


Named after the bird Razorbill (Norwegian: alke).

Well type section

Norwegian well 33/12-2 from 3749 m to 4048 m, coordinates N61°13'31.38", E01°51'25.97".

Well reference sections

UK well 211/29-5 from 3795 m to 4055 m, coordinates N61°04'43.0", E01°45'46.5".
NO well 34/4-C-6H from 2980 m to 3452 m, coordinates N61°31'30.51", E02°12'40.66".


229 m in the type well and 260 m in the reference well.


The Alke Formation is dominated by brick red to red brown, grey and grey-green claystones and mudstones as well as marls which are normally soft, silty and micaceous.


The lower boundary represents a transition from the massive sandstones of the Lomvi Formation. This transition is very sharp as reflected by a sudden increase in the gamma ray log readings.


Distribution of the Alke Formation (click image for full size).


Ladinian - Carnian

Depositional environment

The clay- and mudstones of the Alke Formation is interpreted to be deposited distally to major proximal silica-clastic depositional systems.


In the Snorre Field the interval of the Alke Formation is in certain intervals dominated by sandstone lithology (the “lower Lunde member”). The lower part of the Alke Formation interval of well GB 211/13-1 is also dominated by sandstone lithology. This succession is indicated as unit A (Fig. 5). More information is needed in order to understand the presence of sandstone within the Alke Formation interval. It is not rational to introduce sub-units within the Alke Formation at this stage.

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