Facies changes and paleogeographical implications in the Serravallian of the Lagos-Portimão (Praia da Rocha, southern Portugal)
- Dabrio, Cristino J.
- González Delgado, J.A.
- Armenteros Armenteros, Ildefonso
- Civis, J. Pais, J.
- Alonso Gavilán, G.
- Legoinha, P.
ISSN: 1576-5172
Argitalpen urtea: 2008
Zenbakien izenburua: VII Congreso Geológico de España
Zenbakia: 10
Orrialdeak: 131-134
Mota: Artikulua
Beste argitalpen batzuk: Geotemas (Madrid)
Laburpena
Detailed stratigraphic control and lateral tracing of facies between Praia da Rocha and the adjacent Praia do Vau evidenced that, although the thickness of layers remains essentially homogeneous, the internal composition, grain size and fossil contents change noticeably. Three orders of sequences were distinguished. Smaller-scaled sequences were produced by storms (event beds). Second order sequences are interpreted as generated by a Milankovitch forcing. The larger scale one is observed by the piling of subunits, with assumed eustatic forcing. The prevailing W/SW orientation of paleocurrents measured, and the overall model of dispersion systems, fit in an estuarine pattern of circulation during the Middle Miocene in the North-Betic Strait. Local, gentle diapiric up-warping between Portimão and Albufeira also contributed to water-depth and facies changes.