Data/hora: 06/06/2024 04:36:02

Provedor de dados: | 5
País: | France
Título: | The evolution of a Holocene banner bank controlled by morphodynamics and structural setting of a macrotidal coast: Saint-Brieuc Bay (NW-EUROPE)
Autores: | Traoré, Kalil; Menier, David; Gensac, Erwan; Le Roy, Pascal; Lambert, Clément; Bessin, Paul; Pédoja, Kevin; Duperret, Anne; Le Gall, Romain.
Data: | 2021-09
Ano: | 2021
Palavras-chave: | Sand banks; Banner bank; Holocene climate; Geomorphology; Sea level rise; Tidal gyre.
Resumo: | The morphology and internal structure of the Horaine Bank (Bay of Saint-Brieuc, NW France) are described based on multibeam echosounder and high-resolution seismic datasets coupled with vibro-core data. The Horaine Bank shows large-scale bedforms in the lee of a submerged rocky shoal, which allowed defining it as a Banner Bank. The internal structure of the sandbank reveals four seismic units (U1–U4) on a Cambrian basement (U0). The basal unit U1 is interpreted as reworked lowstand fluvial sediments those infilled micro incised valleys during a rise in sea level. This unit is overlain by paleo-coastal barrier sand-spit (U2) whose development was controlled by swell in the context of a rapid rise in sea level. The successive prograding unit (U3) is interpreted as flooding deposits in continuity with unit U2. The unit U4 is characterized by oblique reflectors oriented in two opposite directions. This last unit, dated post 3500 yr BP, corresponds to migrating dunes superimposed on the bank and observable in the high-resolution bathymetric data. The strong correlation between tidal currents and the apparent clockwise migration of dune crests suggests the presence of a tidal gyre controlling the current dynamics of most of the Horaine bank dunes. This study proposes a new model for the construction of banner banks characterized by the gradual transition of a sand spit to a banner bank during marine transgression and ensuing hydrodynamic variability.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00685/79660/82424.pdf

DOI:10.1016/j.gsf.2021.101183

https://archimer.ifremer.fr/doc/00685/79660/

Editor: | Elsevier BV
Formato: | application/pdf
Fonte: | Geoscience Frontiers (16749871) (Elsevier BV), 2021-09 , Vol. 12 , N. 5 , P. 101183 (16p.)

Fonte:

info:eu-repo/semantics/openAccess

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