Re: HOW DOES SILT STAY AND COLLECT TOGETHER?

How does silt stay and collect together?

Silt is a component of soil and a classification of soil. It is smaller in size than sand and larger than clay particles in the soil. The USDA classifies silt particle sizes as between 0.002 and 0.05 mm.

Unlike clay particles, which are comprised of flat uniform particles, silt is composed of irregular shaped particles, much like small particles of sand. Silt has some of the properties associated with clay, such as cohesion or "stickiness". This is because often times the silt particles are coated with finer clay particles which have a really high cohesion factor. This may answer your question as to why silt can stay in place.

Silt is easily compacted by machinery and may need the addition of organic material to loosen or open the soil up allowing for easier air, water and root accessibility.

Silt (as does most soil) comes from the weathering or erosion of mineral bedrock over long periods of time. Erosion of the bedrock is accomplished through chemical breakdown of the minerals as well as physical erosion from the movement of water or the freeze thaw cycle.

Finer particles, such as silt and clay, are easily transported by water or air. Silt soils that cover large areas of the Great Plains and Mississippi River Valley were deposited during and after the glacial age by the wind. These particular types of soils are referred to as loess (pronounced "luss") happen elsewhere in the world, such as China.

I hope that this explains what you want to know.
Ted

"The Nature and Properties of Soils", 9 ed., N.C. Brady
"Earthscape a Physical Geography", W.M. Marsh

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