2.3.1. Evolution of Lithosphere

The earth was mostly in a volatile state during its primordial stage. Due to gradual increase in density the temperature inside has increased.

In the very early stages of Earth’s formation, the planet was not solid but rather in a chaotic and fluid state. As time went on, the density of the material within the Earth increased. This increase in density raised the temperature, causing different materials to behave differently based on their density.

Think of a pot of boiling water where the heavier ingredients (like vegetables) sink while lighter ones (like oil) float on top. Just like that, as Earth’s materials got hotter and denser, heavier ones sank inwards while lighter ones rose to the surface.

As a result, the material inside started getting separated depending on their densities. This allowed heavier materials (like iron) to sink towards the centre of the earth and the lighter ones to move towards the surface.

This process is known as differentiation, where the Earth's materials separated into different layers based on their weight. Heavier substances, such as iron and nickel, sank to create the core, while lighter substances formed the outer layers, leading to the crust we see today.

Imagine a fruit salad where the heavier fruits like bananas sink to the bottom of the bowl while lighter fruits like blueberries float on the surface. Just like that, Earth’s materials organized themselves into layers, creating the structure of our planet.

With passage of time it cooled further and solidified and condensed into a smaller size. This later led to the development of the outer surface in the form of a crust.

Over millions of years, as the Earth continued to lose heat, it started to cool down. This cooling process caused the outer layer of the molten materials to solidify, forming a solid crust on the surface of the Earth. The solidification marked the beginning of the stable surface we live on today.

Think of a lava lamp. When heated, the wax inside moves freely. When it cools down, the wax solidifies at the bottom. Similarly, as the Earth cooled, it solidified into a crust.

During the formation of the moon, due to the giant impact, the earth was further heated up.

The formation of the Moon is theorized to have occurred after a giant celestial body collided with the early Earth. This cataclysmic event generated immense heat and energy, further influencing the Earth's internal structure and temperature, despite its solid crust.

Consider how hitting a rock generates heat from friction. The collision that formed the Moon similarly generated heat, affecting the young Earth’s surface and internal processes.

It is through the process of differentiation that the earth forming material got separated into different layers. Starting from the surface to the central parts, we have layers like the crust, mantle, outer core and inner core.

Differentiation is the process that allowed the Earth to form distinct layers. As heavier materials sank and lighter materials rose, the Earth developed a multi-layered structure composed of the crust (outer layer), mantle (above the core), outer core (liquid layer), and inner core (solid center). Each layer has unique properties and composition.

Think of a layered cake where different ingredients settle according to weight—lighter ingredients on top and heavier at the bottom. The Earth similarly arranged its materials into layers.

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