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| Titel |
Drainage reorientation and river incision in W Iberia through DEM analysis, cosmogenic nuclide dating and process-based numerical modelling |
| VerfasserIn |
Loreto Antón, Angel Rodes, Daniel Garcia-Castellanos, Raimon Pallàs, Gerardo De Vicente, Antonio Oláiz, Régis Braucher, Didier Bourlès, Fin Stuart |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043990
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| Zusammenfassung |
| The Duero basin, in northern Spain, is the largest of the intraplate Cenozoic basins in Iberia.
This basin is drained by the Duero River, which flows westward through an intraplate granitic
domain (Variscan Basement) before reaching the Atlantic Ocean.The development of the
present fluvial systems in the area is related to a change in the drainage pattern in the
Duero Basin, from endorheic to exorheic. Headward erosion of the Atlantic drainage
network captured the central Iberia rivers and ultimately caused a reorientation of
drainage.
Owing to the scarcity of reliable chronological data, the post-Miocene evolution of the
hydrographic network in Iberia is not well understood. The timing of the capture of endorreic
fluvial systems by the Atlantic network as well as the fluvial incision rates in the region are
poorly constrained. In the Duero Basin no numerical chronology of fluvial terraces is
available and absolute dating techniques are required to better constrain the fluvial network
evolution.
The study area is located on the western border of the Duero Cenozoic basin: an uplifted low
relief landscape where the basement crops-out. Morpho-structure in the area is dominated by
deeply incised fluvial valleys, and by a drainage pattern strongly controlled by tectonic
fractures. The Duero river forms a deep (up to 400 m) gorge called “Arribes del Duero”,
incised mainly in granitic bedrock.
The timing of drainage reorientations and the processes responsible for them can be
constrained by combining tectonic, geomorphic and dating techniques. DEM analysis
of the present drainage network reveals changes in main trunk direction and in
the concavity and steepness of longitudinal profiles in the study area. 15 surface
samples and 3 depth profile samples were collected from bedrock surfaces in the
Arribes de Duero. 10Be concentration data that revealed contrasted patterns of
denudation will be combined with 21Ne data (analyses underway) to help deduce the
age of fluvial incision. Quantifying incision rates is key to constrain the evolution
of drainage in W Iberia, and to improve numerical models of drainage network
evolution. |
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