The term ‘lithosphere’ means crust of the Earth. It includes all big and small landmasses which are found on the Earth.
The large landmasses are called continents. There are seven continents on the Earth.
Functions of the Lithosphere
- It supports all the life-forms on the Earth.
- It is a rich source of minerals. These minerals help in making many useful products.
- It is a major source of fuels such as coal, petrol, etc.
Soil is the uppermost layer of Earth’s crust capable of supporting life. It provides water and minerals to plants for their growth. Without soil there would be no vegetation and hence no animal life. Soil is formed by the breaking down of large rocks over a long period of time. The process of breaking down of rocks into smaller pieces by the action of agents of nature like wind, rain, running streams, glaciers, alternate high and low temperatures and soil organisms is called weathering.
Soil is valuable resources. It is the source of food, clothing, minerals, building material and serves as a habitat to many living organisms. It is the most productive component of land.
Strong winds and water currents carry soil particles with them and deposit them elsewhere. The process of carrying away of the topsoil by various agents like rain, rivers and wind is called soil erosion. Soil erosion has increased due to human activities and is a threat to land as resources. Deforestation, overgrazing, construction of dams, roads and railways, mining and urban encroachment has led to further depletion of productive land. Steps must to be taken to conserve the soil and prevent its erosion. Soil can be conserved by forestation, terrace farming, constructing river embankments, preventing overgrazing and planting plants in deserts.