Consulta: creatorFacets:"Vitali, F"
Registros recuperados: 2
Data/hora: 12/06/2024 12:27:55

Silicate diagenesis in deep-sea sediments from the Tonga forearc (SW Pacific): a strontium and Rare Earth Elements signature
Provedor de dados: 5
Autores: Vitali, F; Blanc, Gerard; Toulkeridis, T; Stille, P.
Sr-87/Sr-86 isotopic ratios, strontium and Rare Earth Element concentrations obtained on volcano-sedimentary rocks and separated clay mineral and zeolite fractions reveal a formation by pore water-volcanic rock interaction for most of the hydrous silicate minerals of the Site 841 ODP collected from the Tonga forearc. Unusual strontium concentrations and isotopic ratios recorded in the Miocene tuffs associated with specific REE patterns indicate that the formation of these hydrous silicates does not follow a simple burial diagenesis model, but was related to the cooling of intruding basaltic sills in the Miocene volcano-sedimentary series. Migration of strontium into the pore water in response to the heat flow induced the formation of Sr-bearing zeolites...
Tipo: Text
Palavras-chave: Tonga; Silicates; Strontium; Terres rares; Diagenèse; Flux thermique; Tonga; Silicates; Strontium; Rare Earth Elements; Diagenesis; Heat flow.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00324/43563/44060.pdf

Geochemical features of site-840 from the tonga platform - a comparison with the other sites from leg-135 odp
Provedor de dados: 5
Autores: Vitali, F; Blanc, G; Larque, P; Samuel, J.
The sedimentary sequence recovered at Site 840 ODP in the Tonga Platform is 597 m thick and ranges in age from Holocene to late Miocene. Here, from the 49 samples analysed, three classes of sediments can be identified, based on their proportion of biogenic carbonate and volcanogenic content. These three classes are comparable with those previously differentiated in the Lau Basin (Sites 834-839) and with some sediments from the Tonga Trench Margin (Site 841). In constrast with neighbouring Site 834-839 sediments from the Lau Basin, the Site 840 sediment composition appears to be exempt of hydrothermal pending material and seems to be characterized only by biogenic and terrigenous andesiticrhyolitic volcanic inputs. The alteration of volcanic material...
Tipo: Text
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00099/21032/18658.pdf