Geomorfología de las terrazas fluviales del tramo bajo del río Guadalquivir. Implicaciones evolutivas

Abstract

Fluvial landforms occupies a considerable area of the study zone. Up to now, these deposits have been interpreted as an extensive piedmont glacis. However, detailed geomorphological mapping has distinguished up to six levels of terraces, with NE-SW orientation. These levels have been correlated with those previously studied in other zones of the Guadalquivir valley using altitudinal, sedimentological and edaphic criteria. An approximate chronology has been established, ranging from the end of the Lower Pleistocene to the beginning of the Upper Pleistocene. It reveals a gradual pushing of the terraces SE-wards on the Neogenic materials of the basin. The most recent levels are sited below the Guadalquivir marshland, with an area of maximum subsidence on a NE-SW axis, coincident with that of the Betic olisthostromic edge in this zone.