versión On-line ISSN 0718-7106
QUEZADA, Jorge; CERDA, José Luis y JENSEN, Arturo. Tectonic and climatic effects in the morphologic configuration of the coastal relief of northern Chile. AndGeo [online]. 2010, vol.37, n.1, pp. 78-109. ISSN 0718-7106.
This work analyzes the morphological features of the western margin of the northern Chile Coastal Cordillera, character-ized by the presence of a major Coastal Cliff The main purpose of this research is to better understand the tectonic and climatic controls on the topography. The methodology used consists basically of a detailed study of the topography with quantitative geomorphic indexes such as incisión grade, hypsometric curves and integráis, thalweg profiles and sinuosity index. These are applied to digital elevation models and satellite images. The main results show that the topography of the western margin of the Coastal Cordillera, exhibits an increasing intensity of the erosión with latitude. This increment is non uniform. The tectonic processes that produced coastal subsidence/uplift and fault activity, and the erosión of the paleotopography of Coastal Cordillera due to processes related with the construction of the Coastal Cliff and increasing rainfall, modify the morphology of the coastal border of northern Chile. The existence and conservation of the Coastal Cliff results from the existance of non-equilibrium between the uplift and erosión rates. Both rates have one-two order magnitude difference, controlled by the extreme hyperarid climate of the Atacama Desert. These conditions prevailed at least for the last 2 m.yrs. The variations in the intensity of the erosión from north to south are interpreted as the result of the southward increase in precipitación by one order of magnitude.
Palabras clave : Geomorphology; Northern Chile; Coastal Cliff; Tectonics; Climate.