What are igneous rocks and their types?
What are igneous rocks and their types?
The cooling and solidification of magma or lava produce igneous rock. Igneous rock can form either below the surface as intrusive rocks or on the surface as extrusive (volcanic) rocks, with or without crystallisation. This magma can come from partial melts of existing rocks in the mantle or crust of a planet. One or more of three mechanisms can produce melting: an increase in temperature, a drop in pressure, or a change in composition.
Types of igneous rock
Following are the two types of igneous rock:
Intrusive igneous rock
These rocks crystallize below the earth’s surface resulting in large crystals as the cooling takes place slowly. Diorite, granite, pegmatite are examples of intrusive igneous rocks.
Extrusive igneous rock
These rocks erupt onto the surface resulting in small crystals as the cooling takes place quickly. The cooling rate is for a few rocks is so quick that they form an amorphous glass. Basalt, tuff, pumice are examples of extrusive igneous rock.
Examples:
- Granite
- Diorite
- Mica
- Quartz
- Basalt
The cooling and solidification of magma or lava produce igneous rock. Igneous rock can form either below the surface as intrusive rocks or on the surface as extrusive (volcanic) rocks, with or without crystallisation. This magma can come from partial melts of existing rocks in the mantle or crust of a planet. One or more of three mechanisms can produce melting: an increase in temperature, a drop in pressure, or a change in composition.
Types of igneous rock
Following are the two types of igneous rock:
Intrusive igneous rock
These rocks crystallize below the earth’s surface resulting in large crystals as the cooling takes place slowly. Diorite, granite, pegmatite are examples of intrusive igneous rocks.
Extrusive igneous rock
These rocks erupt onto the surface resulting in small crystals as the cooling takes place quickly. The cooling rate is for a few rocks is so quick that they form an amorphous glass. Basalt, tuff, pumice are examples of extrusive igneous rock.
Examples:
- Granite
- Diorite
- Mica
- Quartz
- Basalt
