Distribución y características de los depósitos fluviales pleistocenos del subsuelo de la Bahía de Cádiz
- R. Mediavilla 1
- L. Antón-López 1
- C.J. Dabrio 2
- M.A. Perucha 1
- J.J. Santisteban 2
- J.F. Mediato 1
- A. Barnolas 1
- E. Llave 1
- 1 Dirección de Geología y Geofísica, Instituto Geológico y Minero de España
- 2 Departamento de Estratigrafía, Universidad Complutense de Madrid,
ISSN: 1576-5172
Año de publicación: 2004
Título del ejemplar: VI CONGRESO GEOLÓGICO DE ESPAÑA, ZARAGOZA, 12-15 JULIO, 2004
Número: 6
Páginas: 203-206
Tipo: Artículo
Otras publicaciones en: Geotemas (Madrid)
Resumen
Middle to Upper Pleistocene fluvial sediments of the Cádiz Bay occur filling partly two disconnected sub-basins excavated into shallow marine deposits of Pliocene to Lower Pleistocene age, and are buried under fluvial and estuarine Holocene deposits. Subsurface, drill cores, and surface information indicate that the area of the Bay was occupied by a more or less continuous basinduring the Late Pliocene-Lower Pleistocene, but the pattern changed during Middle to Late Pleistocene as revealed by facies analysis and palaeogeographical reconstruction of the fluvial environments. Fluvial deposits are laterally discontinuous, with variable thickness and elongatedtroughs occupied by the coarsest sediments available. Our paleogeographical reconstruction forthis period shows a landscape with two subaerial sub-basins that acted as fluvial valleys during glacially-forced lowstands, with two main fluvial systems flowing constrained by topographical highs.This configuration records the coincidence of very low sea level (regressive conditions) during glacial periods and active neotectonics. The valleys were flooded during the postglacial Holocenetransgression and sea level surpassed the elevations separating the former valleys leading to theapparently simple configuration of the bay.