Flowing Water Conditions Research Articles

Emergence and floating behaviours of post‐settlement juveniles ofMacomona liliana(Bivalvia: Tellinacea)

Observations were made on the behaviour of post‐settlement juveniles of the tellinid bivalve Macomona liliana in the laboratory. Under flowing water conditions the juveniles actively emerged from the sediment and floated in the water column. The emergence and floating behaviours of Macomona liliana are described. The presence of drifting threads in Macomona liliana is also documented.

Facies model for deglaciation in an overdeepened alpine valley (bulle area, Western Switzerland)

This study is concerned with glaciolacustrine sedimentation at the front of the Western Swiss Alps, at the former meeting point of the subsidiary Sarine glacier and the ice stream of the Rhône glacier. During the last glaciation (Late Würmian), these two glaciers eroded into pre-existing glacial sediments and excavated two overdeepened basins in the bedrock. The infill of these basins by glaciolacustrine sediments occurred in two phases. First, diamicts and turbidites were deposited in stagnant or flowing water conditions under the glacier. This episode was followed by deposition of eskers, glaciolacustrine and glaciofluvial outwash, deltaic deposits, alluvial fans and intraglacial moraines in a proglacial lake basin. The glacial sediments are overlain by clay, marl and chalk deposited in a temperate climate. The Quaternary sedimentary succession is a record of rapid climatic change: in 10,000 years, the climate evolved from polar to temperate.

Corrosion in fresh water systems: role of metallurgical factors in stability of steel

Corrosion of fresh water systems are studied. Immersion tests under flowing water conditions were performed for periods upto 7 days. Pipe materials selected for this study included commercial alloys commonly used in fresh water systems such as mild steel. At the end of the long term experiment the materials exposed to the water flow were investigated using the SEM technique. The results showed that the morphology of the surface was dependent on the corrosion behaviour during experimentation. Heat treatment plays an important role in material stability in contact with flowing water.

Fluvio-lacustrine cyclothems from the Oligocene of Hampshire

SummaryEach fluvio-lacustrine cyclothem may include the following lithotypes (in ascending order): (a) irregularly laminated silts and muds; (b) regularly laminated muds and silts; (c) muds with or without molluscan partings and bands; (d) colour mottled muds. Each cycle reflects a change from flowing water conditions (fluvial) to non-flowing water conditions (lacustrine), culminating in some cases with the formation of marsh. Each lithotype is thought to represent the environmental changes which resulted from the silting up of inter-channel depressions on a flood plain. Successive cyclothems possibly reflect renewed flooding following an increase in river level during more pluvial periods.