[ToC]

 

Chester R. Longwell and Richard Foster Flint, Introduction to Physical Geology

KINDS OF MOVEMENT OF ROCK PARTICLES CARRIED IN A STREAM; VERTICAL DISTRIBUTION OF BED LOAD AND SUSPENDED LOAD

 

 

Specific gravity is a very important factor in the transport and deposition of particles of very heavy metallic substances such as gold, and shape is important in flaky minerals such as the micas, but with most particles commonly carried by streams, diameter is the chief factor, because the specific gravity of most of the particles carried by streams is between 2.6 and 2.7, and is therefore nearly constant. The suspended load usually consists of clay or silt or both. Its quantity is measured at gaging stations. The bed load commonly consists of sand or gravel or both. Its quantity is difficult to measure because any sampling device lowered to the stream bed sets up eddies that immediately change the distribution of energy and rock particles in the vicinity of the sample.