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| Panizzo, Virginia; Crespin, Julien; Crosta, Xavier; Shemesh, Aldo; Masse, Guillaume; Yam, Ruth; Mattielli, Nadine; Cardinal, Damien. |
| Combined high-resolution Holocene δ30Sidiat and δ13Cdiat paleorecords are presented from the Seasonal Ice Zone, East Antarctica. Both data sets reflect periods of increased nutrient utilization by diatoms during the Hypsithermal period (circa 7800 to 3500 calendar years (cal years) B.P.), coincident with a higher abundance of open water diatom species (Fragilariopsis kerguelensis), increased biogenic silica productivity (%BSi), and higher regional summer temperatures. The Neoglacial period (after circa 3500 cal years B.P.) is reflected by an increase in sea ice indicative species (Fragilariopsis curta and Fragilariopsis cylindrus, up to 50%) along with a decrease in %BSi and δ13Cdiat (< −18‰ to −23‰). However, over this period, δ30Sidiat data show an... |
| Tipo: Text |
Palavras-chave: Diatoms; Silicon isotopes; Diatom bound carbon isotopes; Seasonal ice zone; Holocene; Southern Ocean. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40157/39098.pdf |
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| Petit, Jerome C. J.; Schafer, Jörg; Coynel, Alexandra; Blanc, Gerard; Chiffoleau, Jean-francois; Auger, Dominique; Bossy, Cecile; Derriennic, Herve; Mikolaczyk, Mathilde; Dutruch, Lionel; Mattielli, Nadine. |
| Zinc stable isotopes measurements by MC-ICP-MS, validated by laboratory intercalibrations, were performed on wild oysters, suspended particles and filtered river/estuarine water samples to provide new constraints for the use of Zn isotopes as environmental tracers. The samples selected were representative of the long range (400 km) transport of metal (Zn, Cd, etc.) contamination from former Zn-refining activities at Decazeville (i.e. δ66Zn > 1 ‰) and its phasing out, recorded during 30 years in wild oysters from the Gironde Estuary mouth (RNO/ROCCH sample bank). The study also addresses additional anthropogenic sources (urban and viticulture) and focuses on geochemical reactivity of Zn in the turbidity gradient and the maximum turbidity zone (MTZ) of... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00277/38852/37390.pdf |
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