Petersburg, West Virginia. Petersburg is a city in Grant County, West Virginia, USA. The population was 2,467 at the 2010 census. It is the county seat of Grant County. Contents.
The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Although a soil could be all sand, all clay, or all silt, that's rare. Instead most soils are a combination of the three.
Soil is a combination of four constituents: mineral material (sand, silt, clay and rock. particles), organic material, air and water. Soil is made from the breaking down of rocks. and organic matter by physical, chemical and biological processes.