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 468

flume experiments (Strong & Paola, 2008). These
results are promising but have been obtained with
extreme parameters, such as sea-level cycle
or rainfall. More studies of real-world systems
are required to calibrate erosion and transport
parameters and quantify the evolution of catch-
ment, fluvial, shelf and sink areas in response to
sea-level; also climate and tectonics.

response to sea-level variations. In particular, the
detailed timing of the erosion and sedimentation
processes, or the diachronicity of erosional sur-
faces, could be investigated at a regional scale.
This study illustrates that simulating sediment
routing systems at a regional scale from source, or
at least from fluvial system or shelf, to sink gives a
better understanding of depositional systems.
This numerical modelling may be used either as a
scientific tool to quantify the interaction between
stratigraphic parameters or as an industrial guide
to reduce uncertainties in exploration and reser-
voir risk assessment (Roure et al ., 2009). More
studies of real-world systems (e.g. Csato et al .,
2012) are required to calibrate transport parame-
ters and to explore the consequences of these non-
linear fluvial laws on shelf and deep-water
turbiditic systems.

CONCLUSIONS

It has been demonstrated that a 3D stratigraphic
forward model can successfully reproduce the evo-
lution of a passive margin either at a regional or
source-to-sink scale. The overall geometry and
stratigraphic architecture of flume and numerical
experiments were analogous. The detailed internal
architecture could not be compared directly due
to the chaotic behaviour of the natural system
and the non-linear response of the numerical
model, but the statistical characteristics such as the
shoreline or centroid evolutions correspond. The
sea-level-forced units were reproduced correctly
with a first, thick, sedimentary unit deposited dur-
ing a sea-level slow cycle and characterised by a
major progradation and aggradation of fluvial sys-
tems and small shallow incised valleys. A second,
smaller, unit during a fast sea-level cycle exhibited
subaerial erosional surface and sinuous narrow
and deep incised valley, toplap truncation and
steep downlap onto the first unit. Finally a com-
posite and complex third unit was composed of a
series of smaller units similar to the second unit.
The 3D numerical model uses a linear slope-
driven, non-linear water-driven diffusion equa-
tion to simulate transport of sediment. A simple
slope-driven diffusion equation induced very
smooth landscapes without any fluvial rivers or
deltas. A linear water-driven diffusion equation
created more complex landscape. Only the non-
linear water-driven diffusion equation was able
to reproduce realistic water flow structure
characterised by sinuous channels and incised
valleys, without using any explicit rules to force
confluences or diffluences of rivers.
Finally, it has been demonstrated that the non-
linear water-driven diffusion equation could be
applied both at a passive margin scale and at a full
source-to-sink system scale. The results of the
source-to-sink model are similar to the local passive
margin model but also provide some new insights
into the evolution of catchment and fluvial areas in

ACKNOWLEDGEMENTS

We thank, gratefully, the Dionisos Consortium
(Chevron, ConocoPhillips, ENI-Agip, ExxonMobil,
GdF-Suez, Petrobras, Respol, Shell, Statoil and
Total). Cornel Olariu and Rory Dalman are
acknowledged for providing highly valuable criti-
cal reviews.

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