3D forward modelling of the impact of sediment transport and base level cycles on continental margins and incised valleys - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 464

1) Evolution of the centroid of the sedimentary system 2) Analysis of the passive margin mass balance 3) Analysis of the source-to-sink mass balance

300

250

T3

T2
T1

200

T T2
T1

150

100

T3
T2
T1

50

Sea-level (m)

0 -50 -100 -150

0 1000 2000 0 1000 2000

0 10 20 30 40

Sedimentation Rate (km 3 /My) Sedimentation Rate (km 3 /My)

Centroid location (km)

Boundary supply or erosion of the source area

Sea-level

Sedimentation on the transition area

Centroid location (Passive margin simulation)

Sedimentation on the sink area

Centroid location (Source-to-sink simulation)

Fig. 7. (1) Comparison of sea-level variations and migration of the centroid of the passive-margin model and of the source-to-sink
model, (2) analysis of the sedimentation and erosion rates in the passive margin model and (3) analysis of the sedimentation and
erosion rates in the source-to-sink model.

Source-to-sink model and filled during the sea-level rise up to the two

plateaus (Fig. 7-5) and finally even inside the
drainage network itself (Fig. 7-6).

The second numerical simulation was performed
to simulate the evolution of a full source-to-sink
system, which included an uplifted drainage area
and a passive margin, separated by two plateaus.
The evolution of this source-to-sink model was
quite similar to that of the passive margin model
(Figs 6 and 7). The drainage networks grew pro-
gressively upstream of the two high plateaus while
a fluvial plain prograded and aggraded down-
stream during the steady phase and slow sea-level
fall (Fig 6-1). This regression was followed by a
backstepping then progradation of a widespread
fluvial plain during the slow sea-level rise (Fig. 6-2).
An increasingly mature network fed a deep incised
valley during the fast sea-level fall (Fig. 7-3) and
once again a widespread fluvial plain backstepped
and aggraded during the fast sea-level rise (Fig. 7-4).
During the second stage (200 ka to 320 ka), with
superimposed slow and fast sea-level cycles, fluvial
valleys were deeply incised during sea-level fall

DISCUSSION

Natural vs. flume experiments

This study explores the use of a non-linear diffu-
sion equation to simulate transport of sediments
at a regional scale. A passive-margin model and a
source-to-sink model were built using data from a
flume experiment. Debates are still very active
about the utility and application of experimental
geomorphology and stratigraphy, as these experi-
ments may be viewed as not representative of real
field-scale systems and as a scaling of all parame-
ters is not possible (Peakall et al ., 1996; Paola
et al ., 2009). Analogue flume modelling presents
well-known scaling problems as all the dimen-
sionless scaling parameters such as the Froude or