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.
Soil is formed as a result of weathering of rocks. There are also many living organisms in the soil. Soil is, in fact a product of the interaction of living organisms with rocks. Soil has many layers. The topmost layer is called the topsoil and is the most fertile. The removal of this topsoil is called soil erosion.