Relationship of Mesozoic graben development, stress, shortening magnitude, and structural style in the Eastern Cordillera of the Colombian Andes
E. Tesón, A. Mora, A. Silva, J. Namson, A. Teixell, J. Castellanos, W. Casallas, M. Julivert, M. Taylor, M. Ibáñez-Mejía, V. A. Valencia, 2013. "Relationship of Mesozoic graben development, stress, shortening magnitude, and structural style in the Eastern Cordillera of the Colombian Andes", Thick-Skin-Dominated Orogens: From Initial Inversion to Full Accretion, M. Nemčok, A. Mora, J. W. Cosgrove
Download citation file:
We use the Eastern Cordillera of Colombia as an example in early stages of inversion orogen showing still modest values of shortening. The style of deformation recorded in this orogenic chain seems to be strongly influenced by two main factors. The first is the pre-compression geometry of the rift basin, conditioning the strong heterogeneity imparted by a trough filled with Jurassic to Neocomian sediments limited by Precambrian and Palaeozoic high-angle walls. The second factor is the orientation of the stress regime with respect to the main normal faults during the inversion. If the stress field is of pure compression, the normal faults are not extensively inverted and the deformation is accommodated mainly in terms of footwall shortcuts. On the other hand, in transpressive regimes the inversion of the former normal faults is more common and the footwall shortcuts are not dominant structures. No significant lateral variations in tectonic shortening are found in the Eastern Cordillera. Finally we emphasize the role of buckle folds in the internal parts of the inversion orogens and give a cautionary note when interpreting these structures in terms of fault-related folding using the well-documented example of the Soapaga fault area.
Figures & Tables
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.