Concentrations of sulfur and carbon, and isotopic compositions of sulfur were determined in sedimentary rocks from a section across the terrestrial Permian^Triassic (P^Tr) boundary in the northern Karoo Basin, South Africa. High concentrations of sulfide produced by sulfate-reducing bacteria were found in the sedimentary rocks at and just below the perceived P^Tr boundary. The ratios of organic...

In this study, we explore the variability of sedimentation conditions (e.g., grain-size, accumulation rate, contamination) according to fluvial depositional environments. Indeed, sediment cores are commonly used as archives natural and anthropogenic activities in hydrosystems, but their interpretation is often complex, especially a context where many factors may affect quality, continuity, reso...

Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability...

Different hydrodynamic conditions can affect both the origin and the quality of organic matter available to bivalve molluscs. I chose 2 environments with very different hydrodynamics (a Mediterranean lagoon open to flow and a closed pond), but similar with regard to temperature, salinity, depth, wind exposure and algae coverage, to investigate this. The lagoon was characterised by active flow a...

Ž . Laboratory experiments were conducted to evaluate the net exchange of organic carbon OC between sediments and overlying water during episodes of resuspension. Surface sediment samples collected from six locations within the Hudson River Estuary and the Inner New York Bight were resuspended in their respective bottom waters for periods ranging from 30 Ž . s to 2 h. After resuspension, dissol...