Evidencias de ajustes aluviales por tectonismo en los arroyos Las Lajas y Santa Catalina, departamento de Río Cuarto, Córdoba

DOFFO, N.; GONZÁLEZ BONORINO, G.,

Córdoba

Congreso; II Congreso Argentino de Cuaternario y Geomorfología; 2006

Escuela de Geología, Univ. Nac. de Córdoba

The fluvial systems are sensitive to tectonic movements, to which they may respond by changes of valley floor slopes. The present paper analyzes the influence of tectonic movements on the Las Lajas Creek and the Santa Catalina Creek, located in Cordoba Province. The study is based on morphostructural evidence and on the change in channel patterns. Unchannelized flow studies and Digital Elevation Models (DEM) serve to define two structural blocks, the Chico low block and the Santa Catalina-Golf high block. On the other hand, the sinuosity, amplitude and wavelength of meanders showed contrasting changes between successive channel reaches in the studied creeks. The results revealed: the influence of Pampean tectonic deformations in the area; the sinuosity and the wavelength of meander loops showed clear relations to changes of channel gradient, so that the channel reaches with high sinuosity and low wavelength coincide with increases of slope in the morphostructural blocks and viceversa. Finally, despite hydrological effects, such as adjustment of base level, the great modification of channel width-depth ratio and the development of terrace sequences, particularly in the Las Lajas Creek, may reasonably be assumed to be intimately associated to the presence of the recognized structural blocks.