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 360

Table 3. ( Continued )

Ichnology

(FA) Facies
associations

General
Description

Sedimentary
structures Facies Internal organisation Ichnofacies Trace Fossils Environmental Interpretation

FA4:
Proximal
to medial
tidally influ-
enced delta
front

F5.2.1,
F5.2.2,
and
F5.1.

Mixed sand-mud
heterolithics.
Fine to very-
fine grained
sandstones.
Laminated to
homogeneous
mudstones.

Parallel lamination,
current-ripple
cross-lamination
(bipolar), com-
bined-flow and
locally wave rip-
ples, climbing rip-
ples, and double
mud drapes.
Parallel lamination
(pinstriped), len-
ticular bedding,
current-ripple
cross-lamination,
symmetric ripples.

Stacked coarsening-upward
and thickening-upward
successions (3 m to 5 m
thick). Current dominated
heterolithics alternate with
combined-flow-dominated
deposits. Heterolithic inter-
vals are overlain by sand-
dominated heterolithics.
Sanding and coarsening-
upward. Pinstripe-laminated
mudstones overlain by the
interbedding of current
and wave-generated,
mud- dominated heterolithics
(maximum thickness of 4 m).

Low to moderate.
Mixed Cruziana
and Skolithos .
Deposit-feeder
structures.

Paleophycus, Chon-
drites, Skolithos,
Rosselia, Planolites,
Teichichnus, and
Rhizocorallium

Tidally influenced delta
front. Mostly in a low-
relief, proximal to medial
prograding delta-front
lobe. More distal than FA3.
Fewer seasonal indicators.

FA5: Proximal
prodelta

F7, F5.4
and
F5.5

Mud dominated
heterolithics.
Poorly lami-
nated, thin
fluid-mud
layers and lam-
inated mud-
stones. Sand
lenses are fine
to very-fine
grained.

Low to moderate.
Deposit-feeder
structures.
Impoverished
expression of
Cruziana

Planolites, Paleo-
phycus , Chondrites ,
Skolithos , and
locally Teichichnus .

Tidal and wave influence
proximal prodeltaic setting.

Skolithos , Rosselia,
Arenicolites, Cylin-
drichnus, Diplocra-
terion Planolites,
Paleophycus ,
Chondrites , and
Teichichnus .

Storm-dominated mouth
bar within the delta-front
area. Seasonality between
fair-weather and inter-
storm periods.

FA6: Storm-
influenced
delta front

F5.3.1,
F5.2.1,
F5.2.2,
and
F4.

Mixed sand-mud
heterolithics.
Fine to very-
fine grained
sandstones.
Laminated to
homogeneous
mudstones.

Parallel lamination,
symmetric ripples,
small-scale and
large-scale HCS,
combined-flow
and current rip-
ples, and lentic-
ular and wavy
bedding.

Thickening and sanding
upward. Medium to thick
beds (30 cm to 60 cm) mud-
dominated heterolithics are
overlain by mixed sand-mud
heterolithics (40 cm to 60 cm
thick) that alternate locally
with 20 cm to 30 cm thick
HCS beds.

Low to moderate.
Dominated
by deposit-
feeders. Mixed
Cruziana and
Skolithos .

FA7: Distal
wave-
influenced
delta front

F5.2.2,
F6.4,
F5.1,
and
F6.3

Mixed sand-mud
heterolithics.
Fine to very-
fine grained
sandstones
(locally
medium
grained).
Laminated to
homogeneous
mudstones

Combined-flow and
current ripples,
chevron lamination,
small-scale HCS,
parallel lamination,
and wavy bedding.

Stacked coarsening-upward
(up to 3 m to 5 m thick).
Sharp-based wavy-bedded
heterolithics overlain and/
or alternating with intensely
bioturbated intervals. Locally,
erosive based cross-bedded
sandstones (20 cm to 30 cm
thick) alternate with the
bioturbated intervals.

Moderate to
intense. Mixed
Cruziana and
Skolithos .

Planolites, Paleo-
phycus , Chondrites ,
Teichichnus, and
subordinate
Cylindrichnus ,
Thalassinoides , and
Phycosiphon .

Wave-influenced delta front.
Moderate to high net
energy levels. Ichnology
suggests a more open-ma-
rine setting compared with
FA3 and FA4.