The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated.
The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long.

This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits.
Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). (lire la suite…)

Ocean Drilling Program (ODP) Sites 1257–1261 recovered thick sections of Upper Cretaceous–Eocene oceanic sediments on Demerara Rise off the east coast of Surinam and French Guiana, South America.

Paleomagnetic and rock magnetic measurements of ~800 minicores established a high-resolution composite magnetostratigraphy spanning most of the Maastrichtian–Eocene.

Magnetic behavior during demagnetization varied among lithologies, but thermal demagnetization steps >200°C were generally successful in removing present-day normal polarity overprints and a downward overprint induced during the ODP coring process. (lire la suite…)

Links, summary text detailing velocity and hydrographic observations, and plots such as, average current speed and locations, drifting buoy positions, sea surface temperature maps, and HYCOM simulations.

The Guiana Current surface water enters the Caribbean primarily between the Windward Islands and between Grenada and the South American continent (Gade 1961).

Model (1950) inferred from observations made by Pillsbury (1889, 1890) that 70% of the total water volume transported into the Caribbean Sea comes from the Guiana Current (Febres-Ortega and Herrera 1976). The section joining the NBC and the Guiana Current along the coast is marked by a relatively constant flow of 10 Sv (Johns et al. 1990). (lire la suite…)

Ce rapport présente les résultats obtenus à mi-étape de l’étude “Dynamique littorale et impacts socio-économiques en Guyane française. Approche par télédétection spatiale” faisant l’objet d’un contrat de consultance entre le CNES et l’IRD.

L’objet de cette consultance est de fournir au CNES, gestionnaire de l’accès au Port de Pariacabo à Kourou, les outils nécessaires pour une meilleure gestion des actions de dragage qu’il a en charge.

Le travail proposé comporte deux volets : (lire la suite…)

Ce rapport concerne la protection contre l’érosion marine en Guyane : il examine la situation du polder rizicole de Mana, le régime sédimentologique du littoral guyanais, l’évolution sédimentologique du littoral de la zone de Mana au cours des dernières décennies, les perspectives d’évolution du littoral de cette zone au cours des prochaines années et propose des mesures susceptibles d’assurer la pérennité du polder à l’horizon 2018. (lire la suite…)