Shortening, structural relief and drainage evolution in inverted rifts: insights from the Atlas Mountains, the Eastern Cordillera of Colombia and the Pyrenees
Julien Babault, Antonio Teixell, Lucía Struth, Jean Van Den Driessche, María Luisa Arboleya, Eliseo Tesón, 2013. "Shortening, structural relief and drainage evolution in inverted rifts: insights from the Atlas Mountains, the Eastern Cordillera of Colombia and the Pyrenees", Thick-Skin-Dominated Orogens: From Initial Inversion to Full Accretion, M. Nemčok, A. Mora, J. W. Cosgrove
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The Atlas, Eastern Cordillera and Pyrenees are thick-skinned thrust-fold belts formed by tectonic inversion of rift basins in continental settings. A comparison of shortening between them shows a gradation from 20–25% in the central High Atlas, to 25–30% in the Eastern Cordillera, and c. 40% in the Pyrenees. Accordingly, there is a structural variation from interior zones with low structural relief and isolated basement massifs in the first two cases, to an axial culmination of stacked basement thrust sheets in the Pyrenees. This results in marked topographic and drainage variation: the High Atlas and Eastern Cordillera contain axial plateaus dominated by structure-controlled longitudinal rivers and orogen flanks with slope-controlled transverse rivers, whereas the Pyrenees show a two-sided wedge profile dominated by transverse rivers. In spite of singularities exhibited by each orogen, we propose that this spatial variation can be understood as reflecting different degrees of evolution in mountain building. Rapidly incising, transverse rivers are capturing earlier longitudinal streams of the Atlas and Eastern Cordillera, thus reducing their axial plateaux, which will eventually disappear into a transverse-dominated drainage. This pattern of landscape evolution may be characteristic of inversion orogens as they develop from initial stages of inversion to full accretion.
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Thick-Skin-Dominated Orogens: From Initial Inversion to Full Accretion
This volume studies the driving dynamic for thick-skin tectonics. It evaluates the role of various factors that control the development of thick-skin architecture. The studied driving dynamics include individual plate movement rates, overall convergence rates, orogen movement sense with respect to mantle flow and pro-wedge versus retro-wedge location. Numerous internal factors that influence the architecture of thick-skinned dominated orogens have been considered. These include the role of the rheology of the deforming layers, the presence or absence of potential detachment horizons, basement buttresses, crustal thickness variations, inherited strength contrasts and the impact of pre-existing anisotropy in thick-skin orogenic deformation. External factors discussed include the role of both syn-tectonic erosion and deposition in deformation.
The study areas begin with worldwide examples and close with a detailed coverage of the Northern Andes natural laboratory, which is characterized by particularly robust data coverage.