Our planet earth is classified into four spheres, which are just a way of creating subsystems of a similar kind. The planet is made of four major components: air, water, land and living things. The realm of our planet comprising of air is known as atmosphere. The realm comprising of water is known as hydrosphere. All living organisms, right from the algae to the plants, the wildlife to human beings, form the biosphere. All land or rocks and ground form the geosphere.
The atmosphere encapsulates the planet. The hydrosphere forms a humongous majority of the surface and also a substantial part of the earth’s crust, including ground water. Biosphere comprising us is typically on the surface and at the most across the ocean floors, sea beds and some underground, which is again just the tip of the crust of the planet.
Geosphere is all the land and rock the planet is made of. The hard rocks on the surface of the earth or crust, the molten magma inside the earth or in the mantle, the mountains that stand tall above the sea level or surface, the hard and cold rocks, minerals and all kinds of hard or molten structures inside the earth including the core form the geosphere.
It must be noted that geosphere is not lithosphere. Many people mistakenly confuse the two. Lithosphere only comprises of the rocks and land that are on the surface of the earth. In other words, lithosphere is restricted to the earth’s crust. The molten magma and all the metal and minerals or solid and liquid components inside the mantle and the core do not form a part of the lithosphere. They do form a part of geosphere.
Everything other than air, water and living organisms is a part of geosphere, from the various types of rocks to the different levels of soil atop the crust, the deposits of oxygen and silicon, iron and magnesium to the gold, diamond and precious gemstones, from the radioactive elements to the fossils, natural gas reserves to coal.
Geosphere may be deemed by many to be the most important of the four spheres or subsections but it cannot be seen in isolation. The formation of the planet’s solid and molten structure is just as much significant as the formation of the other elements, from water to atmosphere because they coexist. Other than living organisms or the biosphere, the three spheres cannot be considered in isolation in an as is condition.