Sand bodies at the shelf edge in the Gulf of Lions (Western Mediterranean): Deglacial history and modern processes

The outer continental shelf of the Gulf of Lions is covered by thick, mainly regressive, sand deposits. A combination of seismic, sedimentological and geochronological methods allows us to demonstrate that a veneer of transgressive sand bodies, few m to less than 1 m thick, reworks these deposits. They take the form of sand ridges and transverse dunes that formed at different periods. In fact, the low-gradient outer shelf of the Gulf of Lions displays a complete record of deglacial history, including not only transgressive deposits that formed during sea-level rise, but also bedfonns that still evolve under episodic high-energy events that occur under more highstand conditions. Core lithology, C-14 dates and regional sea-level curve suggest that the formation of the sand ridges was favoured during a period of deceleration of sea-level rise, such as during the Younger Dryas event. The dunes are part of a "mobile carpet" (here U160). The deposition of this marine sand veneer is possibly related to the interplay between different factors that trigger the turning on/off for bottom currents sand deposition/transport on the outer shelf. In fact, the sands appear to have been reworked intermittently due to high-energy conditions in shallow water depth (currents, wave regime and wind-driven circulation) as well as they form current ridges superimposed to the transgressive deposits in the westernmost part of the studied area (at the Bourcart Canyon's head).

Keyword(s)

Gulf of Lions, Sand transport, Deglacial transgression, Outer shelf, Sand ridges

Full Text

FilePagesSizeAccess
1949.pdf
2919 Mo
Poster colloque
113 Ko
How to cite
Bassetti Maria-Angela, Jouet Gwenael, Dufois Francois, Berne Serge, Rabineau Marina, Taviani M (2006). Sand bodies at the shelf edge in the Gulf of Lions (Western Mediterranean): Deglacial history and modern processes. Marine Geology. 234 (1-4). 93-109. https://doi.org/10.1016/j.margeo.2006.09.010, https://archimer.ifremer.fr/doc/00000/2321/

Copy this text