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Types of Rocks
Types of Rocks Rocks are natural formations that are solid, rigid units of earth's crust. There are two main types of rocks: intrusive and extrusive. Intr...
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Types of Rocks Rocks are natural formations that are solid, rigid units of earth's crust. There are two main types of rocks: intrusive and extrusive. Intr...
Types of Rocks
Rocks are natural formations that are solid, rigid units of earth's crust. There are two main types of rocks: intrusive and extrusive.
Intrusive Rocks
Intrusive rocks are formed when magma, a molten rock that is denser than the surrounding rock, intrudes into existing rock. This can happen when the magma is more viscous and flows more slowly, or when the rock is weak and easily eroded by water. Intrusive rocks include basalt, which is a dark, dense rock, and diorite, which is a light, porous rock.
Extrusive Rocks
Extrusive rocks are formed when molten rock, called lava, erupts onto the Earth's surface. This can happen when the lava is viscous and flows slowly, or when the rock is highly viscous and flows quickly. Extrusive rocks include rhyolite, which is a light, porous rock, and obsidian, which is a dark, dense rock.
Other Types of Rocks
In addition to intrusive and extrusive rocks, there are also sedimentary rocks, which are formed by the accumulation of sediment over time. Sedimentary rocks include limestone, sandstone, and shale. Metamorphic rocks are formed when existing rocks are changed by heat, pressure, or chemical processes. Metamorphic rocks include marble, slate, and gneiss