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.
Clay soil has at least 35% clay particles and the remaining 65% of the soil is made up of sand, silt, organic matter, and open spaces. Because of the nature of clay particles, they form small, flat aggregates (think tiny pancakes). Thus clay soil structure is very dense with little porosity.