Explain with examples the formation of the three types of rocks.
Explain with examples the formation of the three types of rocks.
Three types of rocks are :
- Igneous rock
- Sedimentary rock
- Metamorphic rock
Igneous rock : The Earth's crust is not a continuous layer. It is divided into six main parts that are called tectonic plates. When these plates move away from each other, a gap is formed. During a volcano eruption, magma comes through the gap as lava. It solidifies and forms rocks.
Rocks formed by the solidification of volcanic eruptions are called igneous rocks. Examples of igneous rocks are basalt and granite.
Sedimentary rock : Flowing water and wind continuously deposit silt, soil, and small pieces of rocks into lakes, rivers, and seas. These settle down layer by layer as sediments. Sometimes the remains of dead plants and animals also get trapped in them. These sediments accumulate over long periods of time. The layers at the bottom get compressed and change into hard rocks.
Rocks formed by the accumulation of sediments and compression of the lower layers over long periods of time are called sedimentary rocks.
For example, sandstone, limestone, shale, etc.
Metamorphic rock: The intense heat and pressure below the surface of the earth can bring about changes in the minerals of igneous or sedimentary rocks. Thus the rocks get transformed into different types of rocks. The changed rocks are called metamorphic rocks.
The rocks formed by the transformation of igneous or sedimentary rocks into different kinds of rocks under intense heat and pressure are called metamorphic rocks. For example, marble, slate, gneiss, etc.
Three types of rocks are :
- Igneous rock
- Sedimentary rock
- Metamorphic rock
Igneous rock : The Earth's crust is not a continuous layer. It is divided into six main parts that are called tectonic plates. When these plates move away from each other, a gap is formed. During a volcano eruption, magma comes through the gap as lava. It solidifies and forms rocks.
Rocks formed by the solidification of volcanic eruptions are called igneous rocks. Examples of igneous rocks are basalt and granite.
Sedimentary rock : Flowing water and wind continuously deposit silt, soil, and small pieces of rocks into lakes, rivers, and seas. These settle down layer by layer as sediments. Sometimes the remains of dead plants and animals also get trapped in them. These sediments accumulate over long periods of time. The layers at the bottom get compressed and change into hard rocks.
Rocks formed by the accumulation of sediments and compression of the lower layers over long periods of time are called sedimentary rocks.
For example, sandstone, limestone, shale, etc.
Metamorphic rock: The intense heat and pressure below the surface of the earth can bring about changes in the minerals of igneous or sedimentary rocks. Thus the rocks get transformed into different types of rocks. The changed rocks are called metamorphic rocks.
The rocks formed by the transformation of igneous or sedimentary rocks into different kinds of rocks under intense heat and pressure are called metamorphic rocks. For example, marble, slate, gneiss, etc.
