Eustatic, tectonic and climatic controls on an early syn-rift mixed-energy delta, Tilje Formation (Early Jurassic, Smørbukk field, offshore mid-Norway) - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 367

Sandier/ coarsening upward Sandier/ coarsening upward

100

Top

90

80

70

60

50

FM
HCS

40

30

20

10

Base

0 cm

Base

Fig. 15. Facies associations FA6 and FA7: Storm-influenced and wave-influenced delta-front sanding and coarsening-
upward successions. In FA6, mudstone and mixed sandstone/mudstone heterolithics are commonly overlain by wave-
dominated heterolithics showing overall wavy bedding and local combined-flow (round-crested) and ripple (bidirectional)
cross-lamination. These deposits are commonly capped by thick (up to 1 m) HCS beds. The overlying wave-influenced
delta-front (FA7) units are overall composed of mudstone-dominated deposits that change upwards into mixed sandstone/
mudstone heterolithics showing wave ripples and intensely bioturbated sandstone. FM = fluid muds. Example taken from
reservoir zone Tilje 2 (T2).

The ichnological assemblage and sedimentary
structures indicate that these deposits formed in a
more open and/or distal setting with less fluvial/
tidal influence compared to the tidally influenced
delta-front deposits (FA4).

sandstones (F2) containing large rip-up mud clasts
and/or thick compound fluid-mud layers. These
deposits are overlain by medium and fine-grained
cross-bedded sandstones (F2) alternating with rip-
ple-cross-laminated sandstones (F3) and/or sand-
dominated heterolithics (F5.1). Although the sand
in the succession tends to fine upward, the
abundance of homogeneous mud layers at the base
produces an upward-sanding trend in the lower part
of each succession. Overall, the thickness of the
mud layers decreases to a few millimetres toward
the top of the successions; this thinning reflects an
upward decrease of the suspended-sediment con-
centrations in the water column (Ichaso & Dalrymple,

Facies association 8 (FA8): Tidal-fluvial
channels

FA8 (Fig. 16) consists of sand-dominated, stacked
fining-upward successions. Graded and non-graded
basal conglomerates (F1) are present locally. The
base of each FA8 succession is characterised
by erosionally based, coarse-grained cross-bedded