Gravel Driveway Basics. Cost: $1 to $5 per square foot, though installation costs vary widely depending on where you live and the type of base required. Durability: Lifetime, with proper maintenance. Type of gravel: This depends on your area, but angular shapes are preferred over round.
Soil minerals form the basis of soil. They are produced from rocks (parent material) through the processes of weathering and natural erosion. Water, wind, temperature change, gravity, chemical interaction, living organisms and pressure differences all help break down parent material.
What is soil? Soils are the loose mineral or organic materials found on the earth's surface, usually (or averagely) made up of about 25% air, 25% water, 45% mineral and 5% organic matter (humus, tiny living organisms and sometimes plant residue). It is the stuff that supports rooted plants in a natural environment.