Late Triassic to Early Jurassic climatic change, northern North Sea region: impact on alluvial architecture, palaeosols and clay mineralogy - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 63

Chrono-
strat.

Depositional
Environment

CDP

GR-log

Amundsen Fm

0

Nansen Fm

S1

S2

100

S3

S4

200

S5

300

400

500

600

700

800

900

1000

020406080 100
CDP

Alke Fm

1100

Rivers, lakes Sand Floodplain mud Palaeosol horizons

Fig. 3. Stratigraphy of the Lunde Formation and the Statfjord Group in the Tampen Spur area, northern North Sea,
illustrated by a gamma-log from well 33/12-2, Statfjord Field, with true stratigraphic thickness in metres (m TST) and
channel deposit proportion (CDP). Allostratigraphic units (L12 to L01, S5 to S1) and informal subunits of the Lunde
Formation and the Statfjord Group as applied in this paper are shown together with stratigraphic intervals of fluvial
sandstone assemblages (FSA1 to 6), palaeosol assemblages (PA1 to 5), clay mineral assemblages (CMA1 to 5) and an overall
interpretation of the depositional environment (modified from Nystuen et al . 2008). The Nansen Formation is shallow-
marine and is overlain by the open-marine Amundsen Formation of the Dunlin Group. LLF = lower Lunde Formation,
MLF = middle Lunde Formation, ULF = upper Lunde Formation, LSG = lower Statfjord Group, USG = Upper Statfjord Group.
Depositional models: blue = rivers and lakes, yellow = sand, green = floodplain mud, red = palaeosol horizons. The lower
boundary of the Statfjord Group is according to Deegan & Scull (1977) and Vollset & Doré (1984) (2951 m below KB).