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| Kieffer, B; Arndt, Nt; Weis, D. |
| A bimodal volcanic sequence of 230 m thickness on Skiff Bank, a western salient of the northern Kerguelen Plateau, was drilled during ODP Leg 183. The sequence comprises three main units: a mafic unit of trachybasalt flows sandwiched between two units of trachytic or rhyolitic flows and volcaniclastic rocks. Although interpretation is complicated by moderate to strong alteration of the rocks, their original chemical character can be established using the least mobile major and trace elements (Al, Th, high field strength elements and rare earth elements). High concentrations of alkalis and incompatible trace elements indicate that both mafic and felsic rocks are alkalic. The felsic rocks may have been derived by partial melting of mafic rocks, followed by... |
| Tipo: Text |
Palavras-chave: Ocean Drilling Program; Kerguelen Plateau; Skiff Bank. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33406/31863.pdf |
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| Revillon, Sidonie; Teagle, Damon A. H.; Boulvais, Philippe; Shafer, John; Neal, Clive R.. |
| Hole 1205A was drilled on Nintoku Seamount, which lies in the midportion of the Emperor Seamount Chain. This seamount was emergent similar to 56 Myr ago but was submerged by 54 Ma, so the lavas have endured weathering in both subaerial and submarine environments. We have studied the petrology, mineralogy, and geochemistry of intercalated altered basalts, breccias, and soil samples recovered at Hole 1205A to quantify the chemical exchanges between the seamount and seawater and/ or meteoric fluids. The secondary mineralogy is relatively uniform throughout the section and comprises smectite, Feoxyhydroxides, iddingsite, and Ca-carbonates. Soils are composed of variably altered basaltic clasts in a matrix of kaolinite, smectite, and vermiculite with minor... |
| Tipo: Text |
Palavras-chave: Geochemistry : major and trace element geochemistry; Geochemistry : alteration and weathering processes; Geochemistry : geochemical cycles; Oceanic island; Isotope geochemistry; Chemical fluxes; Alteration; Hole 1205A; Ocean Drilling Program. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2435.pdf |
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| Devries, Tim; Primeau, Francois. |
| Existing methods for inferring the ventilation age of water masses in the ocean using radiocarbon data neglect the effects of diffusive mixing. in the presence of varying atmospheric Delta(14)C, this neglect produces spurious time dependence in the estimated ventilation ages. To correct this deficiency we propose a new method for estimating the ventilation age from sediment core radiocarbon data. The new method is formulated in terms of parameterized age distributions that account for the effects of advective and diffusive transport in the ocean. When applied to simulated radiocarbon data from an OGCM, the method is able to closely reproduce the modeled ventilation age, whereas other methods are not. We also applied the method to sediment-core radiocarbon... |
| Tipo: Text |
Palavras-chave: Ocean Drilling Program; Site 887; Ventilation age; Radiocarbon; Transit-time distribution; Glacial-interglacial. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34197/32870.pdf |
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| Villaseñor, Tania; Tentori, Daniel; Marsaglia, Kathleen M.; Pinto, Luisa. |
| Pleistocene glaciations have promoted important landscape transformations as a result of high rates of erosion and rapid sediment evacuation to adjacent marine basins. In the Patagonian Andes the role of the Patagonian Ice Sheet on landscape evolution, in particular the spatial patterns of glacial erosion and its influence on sediment fluxes, is poorly documented. Here, we investigate the Middle and Late Pleistocene sedimentary record of the continental slope from Ocean Drilling Program (ODP) Site 861, offshore Patagonia (46ºS), to evaluate the link between glaciations, mountain range erosion and continental margin strata formation. Petrographic analysis of the sand‐size fraction (0.063‐2 mm) and ƐNd and 87Sr/86Sr measurements in the silt‐size fraction... |
| Tipo: Text |
Palavras-chave: Glacial erosion; Ocean Drilling Program; Patagonia; Patagonian Ice Sheet; Sediment provenance; Source to sink. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00565/67730/67219.pdf |
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