Consulta: subjectFacets:"Inorganic geochemistry"
Registros recuperados: 3
Data/hora: 09/06/2024 13:58:36

Geochemical methods to infer landscape response to Quaternary climate change and land use in depositional archives: A review
Provedor de dados: 5
Autores: Francke, Alexander; Holtvoeth, Jens; Codilean, Alexandru; Lacey, Jack H.; Bayon, Germain; Dosseto, Anthony.
Understanding and quantifying the processes and geochemical cycles associated with catchment erosion, the development of soils and weathering horizons, and terrestrial habitat change beyond the scales of modern observations remain challenging. Such research, however, has become increasingly important to help predict future landscape change in light of increasing land use and rapid global warming. We herein review organic and inorganic geochemical tools applied to depositional archives to better understand various aspects of landscape evolution on geological time scales. We highlight the potentials and limitations of inorganic geochemical analytical methods, such as major element geochemistry, metal and radiogenic isotopes, and in-situ cosmogenic nuclides,...
Tipo: Text
Palavras-chave: Quaternary landscape evolution; Catchment erosion; Terrestrial habitat change; Land use; Fluvial; Lacustrine; Inorganic geochemistry; Organic geochemistry; Radiogenic isotopes; Metal isotopes; Uranium isotopes; Cosmogenic nuclides.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00632/74383/74084.pdf

Carbon and silica megasink in deep-sea sediments of the Congo terminal lobes
Provedor de dados: 5
Autores: Rabouille, C.; Dennielou, Bernard; Baudin, F.; Raimonet, M.; Droz, Laurence; Khripounoff, Alexis; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Pastor, Lucie; Pruski, A.; Ragueneau, Olivier; Reyss, J.-l.; Ruffine, Livio; Schnyder, J.; Stetten, E.; Taillefert, M.; Tourolle, Julie; Olu, Karine.
Carbon and silicon cycles at the Earth surface are linked to long-term variations of atmospheric CO2 and oceanic primary production. In these cycles, the river-sea interface is considered a biogeochemical hotspot, and deltas presently receive and preserve a major fraction of riverine particles in shallow water sediments. In contrast, periods of glacial maximum lowstand were characterized by massive exports of sediments to the deep-sea via submarine canyons and accumulation in deep-sea fans. Here, we calculate present-day mass balances for organic carbon (OC) and amorphous silica (aSi) in the terminal lobe complex of the Congo River deep-sea fan as an analogue for glacial periods. We show that this lobe complex constitutes a megasink with the current...
Tipo: Text
Palavras-chave: Present; Paleoceanography; South Atlantic; Inorganic geochemistry; Organic geochemistry; Sedimentology-marine cores.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00511/62289/66720.pdf

Late Holocene covariability of the southern westerlies and sea surface temperature in northern Chilean Patagonia
Provedor de dados: 5
Autores: Bertrand, Sebastien; Hughen, Konrad; Sepulveda, Julio; Pantoja, Silvio.
The climate of Chilean Patagonia is strongly influenced by the southern westerlies, which control the amount and latitudinal distribution of precipitation in the southern Andes. In austral summer, the Southern Westerly Wind Belt (SWWB) is restricted to the high latitudes. It expands northward in winter, which results in a strong precipitation seasonality between similar to 35 and 45 degrees S. Here, we present a new precipitation seasonality proxy record from Quitralco fjord (46 degrees S), where relatively small latitudinal shifts of the SWWB result in large changes in precipitation seasonality. Our 1400 yr record is based on sedimentological and geochemical data obtained on a sediment core collected in front of a small river that drains the Patagonian...
Tipo: Text
Palavras-chave: Southern westerlies; Inorganic geochemistry; Paleohydrology; Paleohydroclimatology; Fjord sediments; Southern South America; Chilean Patagonia.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00289/40044/39295.pdf