Etapas e controlo alpino da sedimentação na bacia do Sado (SW de Portugal)
- Autores: Nuno Lamas Valente Pimentel, T. M. Azevedo
- Localización: Cadernos do Laboratorio Xeolóxico de Laxe: Revista de xeoloxía galega e do hercínico peninsular, ISSN 0213-4497, Nº 19, 1994, págs. 229-238
- Idioma: portugués
- Títulos paralelos:
- Alpine control on sedimentation at Sado basin (SW Portugal)
- Enlaces
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Resumen
Tapponnier's (1977) model for the alpine evolution ofthe mediterranean region was firstly adapted for the Tejo-Sado tertiary Basin by Carvalho et al.(1985). At Sado Basin four tectosedimentary units are now defined and paleogeographic reconstructions are confronted with the geodinamic alpine evolution of the area, in order to establish causal effects on sedimentation. Paleogene NE-SW regional compression over Grândola and Torrão faults and secondary traction on Messejana fault, has generated aluvial-fan deposits on these fault-scarps. Miocene evolution is marked by emersion and stability, until a messinian transgression unrecorded elsewhere in the Tejo-Sado Basin. During upper Pliocene, fluvial drainage covered the whole region, without any remarkable tectonic or morphological event. Quaternary "Raña" deposits were dislocated by neotectonic NW-SE regional compression, responsable also for the uplift of Grândola relief (with syntectonic deposits on the coastal plateau) and subsidence of Sado Basin, both over 100m.
