how rocks are formed?
Rocks are formed through a process known as the rock cycle, which involves three types of rocks: igneous, sedimentary, and metamorphic.
1. Igneous Rocks: These rocks are formed from the cooling and solidification of magma or lava. Magma is molten rock found beneath the Earth's surface, while lava is magma that has reached the surface. As magma cools, it solidifies and forms igneous rocks. Depending on the rate of cooling, two types of igneous rocks can be formed: intrusive (cools slowly beneath the surface) and extrusive (cools quickly on or above the surface).
2. Sedimentary Rocks: These rocks are formed through the accumulation and compaction of sediments. Sediments can be derived from weathering and erosion of pre-existing rocks, deposition of organic materials, or the precipitation of minerals from a solution. Over time, these sediments are buried by subsequent layers and undergo compaction and cementation processes to form sedimentary rocks.
3. Metamorphic Rocks: These rocks are formed from pre-existing rocks that undergo physical and chemical changes due to high pressures, temperatures, or the presence of fluids. These changes occur within Earth's crust and transform the rocks into new types of rocks. Examples of metamorphic rocks include marble, formed from limestone, and slate, formed from shale.
It is important to note that the rock cycle is a continuous process, and rocks can transition between different types over millions of years.