|
|
|
|
|
Soulet, Guillaume; Menot, G.; Lericolais, Gilles; Bard, E.. |
During the last decade, a debate arose regarding the timing and pattern of the last reconnection of the Black Sea "Lake" with the global ocean. On a geochemical basis, the radiocarbon age of Black Sea "Lake" surface water, during the time of reconnection, was determined to be similar to 8400 C-14 a. BP. Despite the potential bias induced by the hard water effect in lakes, the reconnection age was calibrated without any reservoir age correction, which led to an estimate of similar to 9400 cal a. BR Since knowledge for the actual calendar age has important hydrologic implications that would provide new insights regarding the mechanism of reconnection, determining the actual calendar age for the last reconnection remains important. Based upon modeling... |
Tipo: Text |
Palavras-chave: Black sea; Reconnection; Reservoir age; Bosphorus sill. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00038/14909/12351.pdf |
| |
|
|
Tachikawa, K.; Vidal, L.; Cornuault, M.; Garcia, M.; Pothin, A.; Sonzogni, C.; Bard, E.; Menot, G.; Revel, M.. |
Holocene eastern Mediterranean Sea sediments contain an organic-rich sapropel S1 layer that was formed in oxygen-depleted waters. The spatial distribution of this layer revealed that during S1 deposition, deep waters were anoxic below a depth of 1800 m. However, whether this boundary permanently existed from the early to the mid-Holocene has not been examined yet. To answer this question, a multi-proxy approach was applied to a core retrieved close to the 1800 m boundary (at 1780 m). We measured the bulk sediment elemental composition, the stable isotopic composition of the planktonic foraminifer Globigerinoides ruber and the abundance of benthic foraminifera since the last deglaciation. The result indicates that authigenic U and Mo accumulation began... |
Tipo: Text |
|
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00291/40252/38634.pdf |
| |
|
|
Vidal, L.; Menot, G.; Joly, C.; Bruneton, H.; Rostek, F.; Cagatay, M. N.; Major, C.; Bard, E.. |
Sediments deposited under lacustrine and marine conditions in the Sea of Marmara hold a Late Quaternary record for water exchange between the Black Sea and the Mediterranean Sea. Here we report a multiproxy data set based on oxygen and strontium isotope results obtained from carbonate shells, major and trace elements, and specific organic biomarker measurements, as well as a micropaleontological study from a (14)C-dated sediment core retrieved from the Sea of Marmara. Pronounced changes occurred in delta(18)O and (87)Sr/(86)Sr values at the fresh and marine water transition, providing additional information in relation to micropaleontological data. Organic biomarker concentrations documented the marine origin of the sapropelic layer while changes in... |
Tipo: Text |
|
Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34243/32642.pdf |
| |
|
|
Bayon, Germain; Toucanne, Samuel; Skonieczny, Charlotte; Andre, L.; Bermell, Sylvain; Cheron, Sandrine; Dennielou, Bernard; Etoubleau, Joel; Freslon, Nicolas; Gauchery, T.; Germain, Yoan; Jorry, Stephan; Menot, G.; Monin, L.; Ponzevera, Emmanuel; Rouget, M. -l.; Tachikawa, K.; Barrat, Jean-alix. |
Over the past decades, rare earth elements (REE) and their radioactive isotopes have received tremendous attention in sedimentary geochemistry, as tracers for the geological history of the continental crust and provenance studies. In this study, we report on elemental concentrations and neodymium (Nd) isotopic compositions for a large number of sediments collected near the mouth of rivers worldwide, including some of the world’s major rivers. Sediments were leached for removal of non-detrital components, and both clay and silt fractions were retained for separate geochemical analyses. Our aim was to re-examine, at the scale of a large systematic survey, whether or not REE and Nd isotopes could be fractionated during Earth surface processes. Our results... |
Tipo: Text |
|
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38733/37249.pdf |
| |
|
|
Eris, K. K.; Ryan, W. B. F.; Cagatay, M. N.; Lericolais, Gilles; Sancar, U.; Bard, E.; Menot, G.. |
In their comment Hiscott and co-authors adhere rigidly to ages and sources for sedimentary units in the subsurface of the Marmara shelf that they have previously reported in their publications from 2002 through 2007. This adherence is in spite of a superior age-depth model from our 13 m-long sediment core that penetrated deeply into the deposits under consideration and in disregard to the results of subsequent more-detailed and full-coverage mapping of the region under scrutiny. The age revisions are dismissed by the authors of the comment as representing sediments severely disturbed during coring. We rebut this criticism. The Bosporus source attributed by them to the sedimentary units sampled and dated by us appears to be driven by their conception that... |
Tipo: Text |
Palavras-chave: Spillway; Black Sea; Marmara Sea; Dardanelles; Bosporus. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5915.pdf |
| |
|
|
|