Consulta: subjectFacets:"Present"
Registros recuperados: 3
Data/hora: 27/07/2024 01:50:59

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

Évolution biologique de la lagune de Nador (Maroc) au cours de la période 1982-1993
Provedor de dados: 5
Autores: Lefebvre, A; Guelorget, O; Perthuisot, Jp; Dafir, Je.
The biogeological evolution of Nador lagoon over the 1982-1993 period was surveyed through water parameters, chlorophyll biomass, macrobenthos and surficial sediments. Comparison of present data with the 1982-83 ones (Guelorget et al., 1984) shows that: the general organization and functioning of the basin (water circulation, biological and sedimentological zonations) remain roughly the same, the global confinement as described by the biological zonation has slightly increased, with an extension of the high confinement zones (zones IV to VI) to the detriment of the low confinement zones, notably zones I and II, the main change has been eutrophication and a dramatic increase elf organic matter inputs and sedimentation, due to increasing urbanization and the...
Tipo: Text
Palavras-chave: Paralic; Confinement; Morocco; Present; Eutrophication.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20404/18071.pdf

Répartition et organisation des foraminifères actuels dans le golfe de Kalloni (Grèce)
Provedor de dados: 5
Autores: Favry, A; Guelorget, O; Debenay, Jp; Lefebvre, A; Perthuisot, Jp.
As part of a global investigation of foraminifera importance in the Mediterranean paralic realm, the distribution of present foraminifera in Kalloni Bay was studied through species determination and counting. From these basic data, density, species richness, Shannon Index and dominance were calculated for several stations covering the whole basin. In addition, a factorial analysis of correspondances between stations and species assemblages was performed. All these methods concur in showing that the organization of foraminifera populations follows sc principal longitudinal gradient from the entrance towards the most continental reaches and a subsidiary transverse gradient. When compared with sedimentological data, the distribution of foraminifera does not...
Tipo: Text
Palavras-chave: Foraminifera; Paralic; Confinement; Greece; Present.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20457/18129.pdf