The provenance of sediments in the Gulf of Lions, western Mediterranean Sea

Abstract

[1] In this study, we undertook a reconnaissance study of sediments provenance in the Gulf of Lions focusing over the last 16 ka. We used geochemical and isotopic tracers to determine the source of sediments and give insight into the weathering conditions prevailing. Sediments samples were selected both onshore and offshore from the western, eastern, and central part of the Gulf of Lions. We analyzed bulk sediments, coarse and fine silt, and clay fractions. Elemental and Nd isotope compositions appeared to differ from one grain size fraction to another one. These are interpreted in terms of zircon addition in the coarse silt fraction for the elemental concentrations and variable sources influences for the Nd isotope compositions. Our results indicate that sediments in the Gulf of Lions mainly originated from the Rhône River watershed although a contribution of Saharan dust is seen in one sample. Influence of Pyrenean small rivers is minor in these samples. Some Sr isotope compositions shifts are interpreted as reflecting variable amounts of chemical weathering that are consistent with published paleoclimatic reconstructions.

Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

“…We suggest that at the end of the LGM/beginning of H1 the Hérault canyon and interfluve area received sediments preferentially from the Hérault drainage basin, which had a higher amount of old carbonates, converse to what is observed at present where sediments mostly originate from the Rhône River (Révillon et al, 2011). This terrestrial source of carbonate sediment would also be prone to the increase of Betaproteobacteria.…”

Distinct control mechanism of fine‐grained sediments from Yellow River and Kyushu supply in the northern Okinawa Trough since the last glacial

“…Sr, Nd, and Pb fractions were chemically separated following conventional column chemistry procedures described in Révillon et al . []. Sr and Nd isotope compositions were measured in static mode on a Thermo TRITON at the PSO (Pôle de Spectrométrie Océan) in Brest, France.…”

Origin and accumulation of trace elements in sediments of the northwestern Mediterranean margin

“…Thirdly, the "y intercepts" (TE/Li for OM = 0) for Ag, Cd, Co, Cr, Cu, Ni and V in canyon cores (G and H) remain unchanged, suggesting a common source for terrigenous TEs, most probably the Rhone watershed as proposed by Révillon et al (2011). This interpretation supposes that authigenic fractions are small for these metals, which, as a first approximation, is reasonable for continental margin sediments (van der Weijden et al, 2006).…”

“…The main inputs of sedimentary material to the GoL shelf are provided by Rhone River floods (discharges >3000 m 3 s -1 ), which are identifiable in the deposits of its proximal delta (Cathalot et al, 2010;Pastor et al, 2011;Révillon et al, 2011;Fanget et al, 2013). Other riverine sources in the same area are poorly preserved due to wave-induced sediment resuspension especially during storms (Guillen et al, 2006 ;Bourrin et al, 2007 ;Kim et al, 2009) and dense shelf-water cascading events Roussiez et al, 2012).…”