Erosion rates in the Guadix-Baza basin have been calculated drawing on a volumetric estimation of sediment loss by river erosion since the late Pleistocene. On this purpose we have performed a reconstruction of the glacis surface dated in 42.6 ka and defined by a calcrete layer that capes the basin infilling. In order to support this age, we presented new 14C radiometric data of three travertine platforms formed later to the beginning of the river entrenchment in the basin and a U/Th dating of a lower calcrete situated some meters below the glacis surface. By comparing the reconstructed geomorphic surface and the present day topography we have calculated the volume of sediment lost by hidric erosion in the entire basin. The resulting erosion rates are between 4.28 and 6.57 m3ha-1yr-1. Individual erosion rates for Guadix and Baza sub-basins (11.80 m3ha-1yr-1 and 1.77 m3ha-1yr-1 respectively) suggest different stages of drainage pattern evolution in both sub-basins. We attribute part of the lower values obtained in the Baza sub-basin as related to the down-throwing due to very recent activity along the Baza fault.
Pérez Peña, V., Azañón, J.m., Azor, A., Della Seta, M., Tuccimei, P., Alonso Zarza, A.m., et al. (2007). Análisis de la erosión diferencial en el pleistoceno superior para las subcuencas de Guadix y Baza.. In P.J. Sanz de Galdeano C (a cura di), LA CUENCA DE GUADIX-BAZA. Estructura, Tectónica Activa, Sismicidad, Geomorfología y Dataciones existentes (pp. 241-262).
Análisis de la erosión diferencial en el pleistoceno superior para las subcuencas de Guadix y Baza.
TUCCIMEI, Paola;
2007-01-01
Abstract
Erosion rates in the Guadix-Baza basin have been calculated drawing on a volumetric estimation of sediment loss by river erosion since the late Pleistocene. On this purpose we have performed a reconstruction of the glacis surface dated in 42.6 ka and defined by a calcrete layer that capes the basin infilling. In order to support this age, we presented new 14C radiometric data of three travertine platforms formed later to the beginning of the river entrenchment in the basin and a U/Th dating of a lower calcrete situated some meters below the glacis surface. By comparing the reconstructed geomorphic surface and the present day topography we have calculated the volume of sediment lost by hidric erosion in the entire basin. The resulting erosion rates are between 4.28 and 6.57 m3ha-1yr-1. Individual erosion rates for Guadix and Baza sub-basins (11.80 m3ha-1yr-1 and 1.77 m3ha-1yr-1 respectively) suggest different stages of drainage pattern evolution in both sub-basins. We attribute part of the lower values obtained in the Baza sub-basin as related to the down-throwing due to very recent activity along the Baza fault.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
