The Earth's crust is constantly changing through The Rock Cycle interactions and processes that transform rocks from one type to another over millions of years.
Difference between igneous, metamorphic, and sedimentary rocks can be understood through their unique formation processes. Igneous rocks form when molten magma or lava cools and solidifies, creating crystals of varying sizes depending on how quickly the cooling occurs. Common examples include granite and basalt. Sedimentary rocks develop when layers of sediment (broken rock pieces, minerals, and organic matter) are compressed and cemented together over time, forming rocks like sandstone and limestone. Metamorphic rocks are created when existing rocks undergo intense heat and pressure deep within the Earth, causing their mineral structures to change - examples include marble (transformed limestone) and slate (transformed shale).
Formation and transformation of rocks through weathering and erosion is a continuous cycle that shapes our planet's surface. Physical weathering breaks down rocks through temperature changes, frost action, and plant root growth, while chemical weathering alters rock composition through reactions with water, oxygen, and acids. Erosion then transports these weathered materials to new locations where they may become sediments. These sediments can be buried, compressed, and eventually form new sedimentary rocks. Through tectonic forces, any type of rock can be pushed deeper into the Earth where heat and pressure can transform them into metamorphic rocks, or they may melt completely to form new igneous rocks when cooled. This ongoing cycle demonstrates how rocks are not permanent features but rather part of a dynamic system that continuously recycles Earth's materials through various geological processes over millions of years.
