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| Titel |
Influence of dynamic topography on landscape evolution and passive continental margin stratigraphy |
| VerfasserIn |
Xuesong Ding, Tristan Salles, Nicolas Flament, Patrice Rey |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250147600
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| Publikation (Nr.) |
 EGU/EGU2017-11788.pdf |
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| Zusammenfassung |
| Quantifying the interaction between surface processes and tectonics/deep Earth processes is
one important aspect of landscape evolution modelling. Both observations and results from
numerical modelling indicate that dynamic topography - a surface expression of time-varying
mantle convection - plays a significant role in shaping landscape through geological time.
Recent research suggests that dynamic topography also has non-negligible effects on
stratigraphic architecture by modifying accommodation space available for sedimentation.
In addition, dynamic topography influences the sediment supply to continental
margins.
We use Badlands to investigate the evolution of a continental-scale landscape in response
to transient dynamic uplift or subsidence, and to model the stratigraphic development on
passive continental margins in response to sea-level change, thermal subsidence and
dynamic topography. We consider a circularly symmetric landscape consisting
of a plateau surrounded by a gently sloping continental plain and a continental
margin, and a linear wave of dynamic topography. We analyze the evolution of river
catchments, of longitudinal river profiles and of the χ values to evaluate the dynamic
response of drainage systems to dynamic topography. We calculate the amount of
cumulative erosion and deposition, and sediment flux at shoreline position, as a
function of precipitation rate and erodibility coefficient. We compute the stratal
stacking pattern and Wheeler diagram on vertical cross-sections at the continental
margin.
Our results indicate that dynamic topography 1) has a considerable influence on drainage
reorganization; 2) contributes to shoreline migration and the distribution of depositional
packages by modifying the accommodation space; 3) affects sediment supply to the
continental margin. Transient dynamic topography contributes to the migration of drainage
divides and to the migration of the mainstream in a drainage basin. The dynamic uplift
(respectively subsidence) of the source area results in an increase (respectively
decrease) of sediment supply, while the dynamic uplift (respectively subsidence) of the
continental margin leads to a decrease (respectively increase) in sedimentation. |
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