Mud is transported to the Dutch delta area from the Rhine, Waal, Maas and Scheldt rivers (resp. 0,6; 2,5; 0,7 and 0,7 million tons/year). Above, in the Rotterdam Waterway about 3,5 million tons of mud per year are brought in from the sea. The mud of the u

Abstract

Sediments in the anoxic reaches of the Veerse Meer, a tideless basin in the southwest Netherlands, possess certain physical properties which are directly dependent upon the geochemical environment in which they are accumulating. High values of water content and correspondingly low values of bulk density (unit weight) and shear strength were observed in sediments deposited in low oxygen to anoxic waters (-12 m to -20 m depth). Plasticity increased regularly with depth with highest plasticity found in the most highly reduced sediments at -20 m. One-dimensional consolidation analyses showed rapid consolidation and almost complete lack of rebound. Stress-strain diagrams show little or no reloading curves and are typical of underconsolidated or remolded sediments in which interparticle bonding is minimal. Gas generation and bubble ebullition with swelling is believed to retard normal gravitational consolidation and inhibit fabric development through continual agitation and physical manipulation of sediment particles. Both conditions (i.e., underconsolidation and remolding) exist as a direct result of methanogenesis.