Which type of igneous rock is formed from the cooling and solidification of magma beneath the Earth's surface?

Which type of igneous rock is formed from the cooling and solidification of magma beneath the Earth's surface?

• A. Extrusive igneous rock
• B. Basaltic rock
• C. Intrusive igneous rock
• D. Volcanic rock

Answer: (C)

Igneous rocks are classified based on where they form and how quickly they cool. Intrusive igneous rocks, also known as plutonic rocks, are formed from the cooling and solidification of magma beneath the Earth's surface. This type of rock typically has a coarse-grained texture because the slow cooling process allows larger crystals to form. The formation of intrusive igneous rocks occurs in environments where magma is trapped beneath layers of rock, providing the necessary heat for it to gradually cool. Common examples include granite and diorite. In contrast, extrusive igneous rocks, formed from lava that cools quickly on the Earth's surface, usually display a finer-grained texture. Meanwhile, volcanic rock is essentially a synonym for extrusive rock and does not refer specifically to the formation beneath the surface. Basaltic rocks are a type of extrusive rock primarily composed of basalt, which also cools quickly at the surface.

Igneous rocks are classified based on where they form and how quickly they cool. Intrusive igneous rocks, also known as plutonic rocks, are formed from the cooling and solidification of magma beneath the Earth's surface. This type of rock typically has a coarse-grained texture because the slow cooling process allows larger crystals to form.

The formation of intrusive igneous rocks occurs in environments where magma is trapped beneath layers of rock, providing the necessary heat for it to gradually cool. Common examples include granite and diorite.

In contrast, extrusive igneous rocks, formed from lava that cools quickly on the Earth's surface, usually display a finer-grained texture. Meanwhile, volcanic rock is essentially a synonym for extrusive rock and does not refer specifically to the formation beneath the surface. Basaltic rocks are a type of extrusive rock primarily composed of basalt, which also cools quickly at the surface.