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.
Describe the contents of the three soil horizons found in most mature soils. The A horizon, or topsoil, contains a mixture of mineral matter and organic matter, as well as many insects, fungi, and microorganisms. The B horizon, or subsoil, contains fine clay particles washed out of the A horizon. The C horizon contains partially weathered parent material.