A STUDY OF THE MACROMOLECULAR CONSTITUENT S IN THE SUSPENDED MATTER OF THE RHONE DELTA USING CURIE-POINT PYROLYSIS - IMPLICATIONS IN THE FORMATION OF THE BENTHIC NEPHELOID LAYER

The polymeric organic matter of the River Rhone and its fate in the de ltaic zone were studied using Curie-point pyrolysis gas chromatography -mass spectrometry. This approach allowed differentiation between the allochthonous and autochthonous components of the suspended particles. Contamination of the waters, possibly originating from the industrial ized Gulf of Fos was evidenced in some surface-water pyrolysates. The suspended matter in the benthic nepheloid layer had a similar fingerpr int to that observed in riverine suspensions. The abundance of polysac charide-derived compounds in the layer and in the river suggested that these molecules could be involved in flocculation processes when fres h and saline waters mix.