Search results for "géologie"
showing 10 items of 13 documents
A geological field trip to the Côte d'Ivoire-Ghana transform margin
1998
Abstract During the Equanaute survey (June 1992), fourteen submersible dives were performed between 4950 and 2250 m water depths across the southern slope of the Cote d'Ivoire-Ghana Marginal Ridge (CIGMR), in the eastern Equatorial Atlantic. The CIGMR, a high-standing topographic marginal ridge along the Cote d'Ivoire-Ghana transform margin, is believed to result from a complex structural evolution due to the specific wrench-related rifting between Western Equatorial Africa and Northeastern Brazil, in Early Cretaceous times. In this paper we report and discuss geological observations made during dives, and sample analyses to resolve the lithology, paleoenvironmental conditions, age and orig…
Taxonomy 2.0: computer-aided identification tools to assist Antarctic biologists in the field and in the laboratory
2020
Species inventories are essential to the implementation of conservation policies to mitigate biodiversity loss and maintain ecosystem services and their value to the society. This is particularly topical with respect to climate change and direct anthropogenic effects on Antarctic biodiversity, with the identification of the most at-risk taxa and geographical areas becoming a priority. Identification tools are often neglected and considered helpful only for taxonomists. However, the development of new online information technologies and computer-aided identification tools provides an opportunity to promote them to a wider audience, especially considering the emerging generation of scientists…
Les anges musiciens aux XIVe-XVe siècles, figuration et idéalisation du cosmos divin
2002
Andrea von Hülsen-Esch et Jean-Claude Schmitt,; International audience
Le Clos-Vougeot et sa perrière
2010
Une spéléogenèse à acide sulfurique dans le piémont nord-pyrénéen ?
2018
Tout au long de l’histoire de structuration des Pyrénées, le jeu des grands accidents tectoniquesfont de la zone de piémont nord-pyrénéen une aire privilégiée de circulation de fluides. Parmiceux-ci, la présence de saumures profondes riches en CO2 et H2S a été attestée dans les réservoirspétroliers sud-aquitains d’âge Crétacé. Impliqués dans des processus de migration vers les margesde bassin, ces fluides sont susceptibles de former des cavités dans l’encaissant calcaire là où lesremontées d’H2S entrent en contact avec du dioxygène, produisant ainsi du H2SO4. C’est cettehypothèse de spéléogenèse à acide sulfurique (SAS) que la présente étude cherche à explorer dansles Pyrénées.Les premières…
Le Kimméridgien du Barrois dans le département de l'Aube (France)
2012
Dissolved silica in the Garonne River waters : changes in the weathering dynamics
2000
The major ion chemistry of the Garonne River is indicative of seasonal variations in the weathering dynamics of the drainage basin. Using the geochemical model MEGA for calculation of the contribution of atmospheric CO2 to the total bicarbonate fluxes exported by the Garonne River allows estimations of the concentrations of the major dissolved elements that originate from silicate- and carbonate-rock weathering. The molecular ratio SiO2/Al2O3 was calculated for the 1989–1992 period to identify the main type of weathering in the Garonne River, and montmorillonite was shown to be the major mineral occurring in the weathering products. The seasonal variations of the SiO2/Al2O3 ratio also showe…