Melke Formation (Melkeformasjonen)
(From NPD Bulletin no. 4)
Viking Group
Name
The Norwegian word for milt or soft roe. This unit corresponds to the
informal Engelvaer formation (H2-1).
Well type section
Well 6506/12-4
(Statoil), coordinates 65°12'46.97"N, 06°43'30.37"E, from 3979.5 m to 3863
m (Fig. 21). One core, 8 m recovery, including formational base.
Well reference section
Well 6407/2-2
(Saga Petroleum), coordinates 64°59'39.64"N, 07°31'53.08"E, from 2461 to
2417 m, (Fig. 23). One core, 2 m recovery, including the base.
Thickness
116.5 m in the type well, 44 m in the reference well.
Lithology
Dominantly claystone, with siltstone and limestone interbeds and stringers
of sandstone. The claystone is dark grey to dark brown and slightly
calcareous.
Basal Stratotype
The base is defined by a sharply increasing gamma ray response at the
contact between the underlying sandstones of the
Garn Formation and the claystones of the
Melke Formation.
Lateral extent and variation
The formation was deposited throughout the Haltenbanken-Trænabanken area
and is locally absent on structural highs. The formation may attain
thicknesses of several hundred metres in down-flank basinal situations.
The formation also shows lateral variation in lithology, being more silty
or having more frequent limestone beds in some areas. Deposition of the
unit's mudstones commenced earlier on Trænabanken than elsewhere (Fig.
6).
The unit subcrops beneath the Quaternary on the eastern part of the
Trøndelag Platform as evidenced by several shallow cores (Bugge et al.
1984).
Age
Bajocian to Oxfordian
Depositional environment
The Melke Formation was deposited in an open marine environment.
Correlation
The Melke Formation is comparable to the Heather
Formation of the North Sea. The upper parts of the Melke Formation are
time equivalent to the Fuglen Formation in the Hammerfest Basin.
