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| Chang, Alice S.; Pichevin, Laetitia; Pedersen, Thomas F.; Gray, Victoria; Ganeshram, Raja. |
| A high-resolution, 55 kyr long record of chalcophile and redox-sensitive trace element accumulation (Ag, Cd, Re, and Mo) from MD02-2515, western Guaymas Basin, is investigated in conjunction with patterns in stratigraphy and productivity. High opal concentrations (~59 wt. %), representing increased diatom production, coincide with laminated sediments and dilute the concentrations of organic carbon (Corg) and metals. A similarity between opal and normalized Corg, Ag, and Cd concentrations suggests delivery to the sediments by diatom export production, while patterns in normalized Re and Mo accumulation suggest a different emplacement mechanism. Although Mo enrichment in organic-rich, laminated sediments typically represents anoxic conditions at other... |
| Tipo: Text |
Palavras-chave: Productivity; Redox; Trace elements; Laminated sediments; Guaymas Basin; Northeast Pacific Ocean. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40566/39461.pdf |
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| Singh, Arun Deo; Jung, Simon J.a.; Darling, Kate; Ganeshram, Raja; Ivanochko, Tara; Kroon, Dick. |
| Productivity in the Arabian Sea is one of the highest in the world. It is controlled by seasonally reversing monsoonal wind-driven upwelling of nutrient-rich deeper waters which fuel phytoplankton growth. The detailed history of upwelling-induced productivity in the eastern Arabian Sea is unknown. Here we present paleoproductivity records from a composite sediment core at the millennial scale during the last 80 kyr B. P. These records are based on relative abundance counts of planktonic foraminifera and organic carbon contents, which are shown to mainly vary in concert. The eastern Arabian Sea upwelling-induced productivity was higher in the glacial period than in the Holocene, but it fell repeatedly on millennial timescales. These productivity declines... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33823/32474.pdf |
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