The Garn Formation (Bajocian-Bathonian) in the Kristin Field, Halten Terrace: its origin, facies architecture and primary heterogeneity model - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 516

HALTEN TERRACE REGION

CHRONOSTRAT IGRAPHY GP. FORMATIONS DEPOSITS

Callovian

Offshore mud

MELKE

Bathonian
Bajocian

Shallow-marine & deltaic
sands
Offshore mud
Mainly deltaic deposits

GARN

NOT

Aalenian

ILE
ROR

Offshore mud with
fan-deltaic sand wedges
Heterolithic tidal &
deltaic deposits

Toarcian
Pliensbach.
Sinemurian
Hettangian

TOFTE

TILJE

Mainly terrestrial
(coal-bearing alluvial &
lower delta-plain deposits)

ÅRE

Rhaetian

“GREY BEDS”

Terrestrial
(red to non-red ￿uvial
sands & thick
playa-lake salts)

Norian

Halites

Carnian

“RED BEDS”

Fig. 3. The Upper Triassic to Middle Jurassic stratigraphy of the Halten Terrace (modified from Martinius et al ., 2005;
based on the original proposal of Dalland et al ., 1988).

The Jurassic latitude of the Halten Terrace was
between 49° N and 53° N (Smith et al ., 1994) and
the regional climate was warm and probably sea-
sonal (Hallam et al ., 1994). The elevated area to
the west of the Kristin Field, referred to as the
Grip High (Johannessen & Nøttvedt, 2008), was
subject to uplift and subaerial erosion in the
Early to Middle Jurassic, before collapsing in
the Cretaceous (Doré, 1992; Brekke, 2000; Brekke
et al ., 2001). Sediment deposition occurred in the
Halten Terrace and adjacent Trøndelag Platform
to the east (Figs 1 and 2B). This south-trending
basin had a fault-related physiography and acted
as a narrow seaway, ~250 km wide and > 1500 km
long, linking the Boreal Sea with the Tethys Sea to
the south and hosting wave-dominated to tide-
dominated sedimentation (Gjelberg et al ., 1987;
Doré, 1992; Brekke et al ., 2001; Martinius et al .,
2005; Quin et al ., 2010). Sand was delivered from
the Grip High shoreline (Jongepier et al ., 1996;
Ehrenberg et al . 1998; Brekke et al ., 2001;
Johannessen & Nøttvedt, 2008), which probably
included small river or fan deltas (Gjelberg et al .,
1987; Dalland et al ., 1988). The Scandinavian
shoreline was located > 200 km to the east (Smith
et al ., 1994; Doré, 1992; Brekke et al ., 2001, fig. 18)
and the adjoining Trøndelag Platform was a mud-
dominated shelf area.
Evidence from the Jameson Land of East
Greenland indicates a narrower parallel branch of
the Jurassic seaway on the western side of the
Grip High (Doré, 1992; Brekke et al ., 2001; Quin

et al ., 2010, fig. 1b), where southward marine
transport with deposition of tidal sand bodies has
been recognised (Surlyk, 1991, 2003).

Jurassic stratigraphy

The Mesozoic stratigraphy of the Halten Terrace
(Fig. 3) was established by Gjelberg et al . (1987)
and Dalland et al . (1988). Salt-bearing terrestrial
Triassic deposits are overlain by the Åre Formation
(Hetangian to Sinemurian) composed of coal-
bearing alluvial and tidally influenced delta-
plain deposits. The overlying Tilje Formation
(Pliensbachian) consists of heterolithic deposits
representing tide-dominated coastal plains, deltas
and bays or estuaries. The transgressive succes-
sion culminates in the Ror Formation (latest
Pliensbachian to Toarcian) composed of neritic
offshore mudstones intercalated with the westerly
deltaic sandstone wedges of the Tofte Formation
(Fig. 3). The Ile Formation (late Toarcian to
Aalenian) comprises heterolithic deposits of tide-
dominated deltas overlain by the bioturbated off-
shore mudstones of the Not Formation (Aalenian
to earliest Bajocian), which is another transgres-
sive succession, although passing into sand-rich
heterolithic tidal deposits near the top.
The overlying Garn Formation (Bajocian to
Bathonian) is limited in its extent to the Halten
Terrace (Brekke et al ., 2001) and is a time-
stratigraphic equivalent of the Brent Group in the
northern North Sea (Helland-Hansen et al ., 1992).