Data/hora: 01/06/2024 10:16:01

Provedor de dados: | 5
País: | France
Título: | Le comblement de la ria de Gernika (golfe de Gascogne) à l'Holocène terminal
Autores: | Pascual, A; Weber, O; Rodriguez-lazaro, J; Jouanneau, Jm; Pujos, M.
Data: | 1998-03
Ano: | 1998
Palavras-chave: | Microfaune; Sédimentation; Holocène terminal; Ria de Gernika; Microfauna; Sedimentation; Late Holocene; Ria de Gernika.
Resumo: | A study of the recent sedimentation of the ria de Gernika (Bay of Biscay) is undertaken to characterise different steps of its Holocene filling. Sedimentological and micropalaeontological analysis of six cores sampled in the ria, completed with absolute dating (C-14, and based upon Pb-210 exc.), allow us to identify three phases in the filling of the ria that are Limited by two transgressive shifts (3500 and 2500 yr. B.P.) already described in other areas of the Bay of Biscay. In the first phase, lithologies as well as benthic foraminifera and ostracode assemblages are typical of coastal marine palaeo-environment. During the second phase the euryhaline waters progessively occupy the central area of the estuary. Here the presence of allochthonous microfauna, particularly of planktonic foraminifera, indicates an increase of exchanges with marine waters that can reach the inner areas of the estuarine system. The last phase (2500 yr. B.P. to the present), which corresponds to the recent and active sedimentation, is marked by an impoverishment of the microfaunas, the filling of some channels and the increase of salt marshes. The estimated sedimentation rate for the upper decimetres of the cores (0.73-1.29 cm . yr(-1)) shows faster sedimentary filling of the ria with anthropic action evidenced by the presence of metallic contaminants and hypohaline microfauna.
Tipo: | Text
Idioma: | Francês

Identificador:

http://archimer.ifremer.fr/doc/00326/43684/43237.pdf

DOI:10.1016/S0399-1784(98)80013-3

http://archimer.ifremer.fr/doc/00326/43684/

Editor: | Gauthier-villars/editions Elsevier
Formato: | application/pdf
Fonte: | Oceanologica Acta (0399-1784) (Gauthier-villars/editions Elsevier), 1998-03 , Vol. 21 , N. 2 , P. 263-269

Fonte:

Elsevier, Paris

info:eu-repo/semantics/openAccess

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