The rocks present in the parent rock are weathered by temperature, wind, rain, frost, microorganisms, plants and animals. The weathering of rocks breaks the large particles into smaller particles which are soil particles. The soil particles are responsible for the characteristic of the soil profile of a place. A soil profile shows the arrangement of different layers of the soil. The uppermost layer of the soil is rich in humus (organic matter) and microorganisms and is therefore very fertile. Soil formed thus contains soil particles (gravel, sand, silt, and clay of different sizes), humus, soil air, soil water and soil organisms.

The formation of soil occurs as a result of weathering of rocks. Sun, water, wind, and living organisms play a vital role in this process. Sun- Rocks expand in the daytime due to sun's intense heat and then cools and contract during the night time. This regular expansion and contraction cause cracks which eventually leads to the breakdown of rocks. Water- Water helps in soil formation either by fast flow or freezing. The water freezes in soil cracks resulting in expansion and breaking of rocks. The fast flowing of water causes rocks to weather slowly and transfer of soil particles to new places. Wind- Strong winds and storms further break the rocks and transfers the soil to different places. Living Organisms- Lichens growing on rock surfaces release chemicals that convert the rocks into powder and lead to the formation of the thin soil layer. Other small plants like mosses grow on the surface of rocks, which causes the rocks to break further.

Earlier the surface of the earth was covered with rocks and there was no soil on earth. The sun heated the rocks, and the rain made them cold. This continued for thousands of years. Due to the changes in the weather, the rocky surface began to crack. The fast flowing rain and river water entered these cracks and broke the rocks into smaller pieces. These pieces further became fine due to the action of air and water, and thus soil was formed. This process is called weathering.

Soil is formed when rocks break down into tiny pieces due to repeated heating and cooling by the sun, rain and wind. This is called weathering. When it rains water gets into the cracks in the rocks and remains there. In cold weather, it freezes, exerts pressure and breaks the rocks. This repeated weathering over thousands of years breaks the rocks into small pieces of sand. This results in the formation of soil. It is a continuous process.