Volcanic rocks and plutonic rocks are both types of igneous rocks, but they are formed in different ways. Volcanic rocks form when magma erupts from a volcano, while plutonic rocks form when magma cools and crystallizes underground. Plutonic rocks are usually more coarse-grained than volcanic rocks, and they contain more crystals. Volcanic rocks can be further divided into two groups: extrusive igneous rocks, which form from lava that is ejected from the volcano, and intrusive igneous rocks, which form when magma crystallizes inside the volcano.
What are Volcanic Rocks?
Volcanic rocks are formed when hot molten rock, ash, and gas escape from a volcano. The molten rock, called magma, is heated by the earth’s heat. This can happen when the magma is in the mantle or when it is in the crust. When the magma is in the mantle, it is called a mantle plume. When it is in the crust, it is called a hot spot.
- The magma rises to the surface and can break through the crust. This can happen explosively or slowly over time. Volcanoes that erupt explosively tend to have very violent eruptions. Volcanoes that erupt slowly tend to have less violent eruptions. Volcanic rocks can be classified according to their composition.
- The three main types of volcanic rocks are basalt, andesite, and rhyolite. Basaltic rocks are made up of mostly iron, magnesium, and calcium. Andesitic rocks are made up of mostly silicon, aluminum, and oxygen. Rhyolitic rocks are made up of mostly silica and water. Volcanic rocks can also be classified according to their texture.
- The four main types of textures are aphanitic, porphyritic, glassy, and vesicular. Aphanitic rocks have small crystals that cannot be seen by the naked eye. Porphyritic rocks have large crystals that can be seen with the naked eye. Glassy rocks have no crystals and look like glass.
Vesicular rocks have small holes that were created by gas bubbles that were trapped in the magma as it cooled. Volcanic rocks are used for many things including making jewelry, statues, sculptures, and countertops. They are also used in construction and road building. Volcanic rocks can be found all over the world.
What are Plutonic Rocks?
Plutonic rocks are a type of igneous rock that forms when magma cools slowly beneath the earth’s surface. The word “plutonic” comes from the Greek god Pluto, who was thought to rule the underworld. Plutonic rocks are also sometimes called intrusive rocks because they form when magma intrudes into existing rock layers. Because they cool slowly, plutonic rocks have large crystals. The most common plutonic rocks are granite and gabbro. Plutonic rocks make up a large part of the earth’s crust and are used in construction, road building, and landscaping.
Difference between Volcanic Rocks and Plutonic Rocks
Volcanic rocks and plutonic rocks are two types of rocks that are formed through different processes.
- Volcanic rocks are formed when hot molten rock, called magma, is erupted from a volcano and cools quickly.
- Plutonic rocks are formed when magma cools slowly beneath the Earth’s surface. The main difference between these two types of rocks is their grain size.
- Volcanic rocks have small grains because they cool quickly, while plutonic rocks have large grains because they cool slowly. Volcanic rocks are also often lighter in color than plutonic rocks because they contain less iron and magnesium.
Another difference between these two types of rocks is their chemical composition. Volcanic rocks are usually rich in silica, while plutonic rocks are typically lower in silica content.
Conclusion
Volcanic rocks are created when magma and ash escape from a volcano. The molten rock (magma) is less dense than the solid rock around it so it rises to the surface. When it reaches the surface, gas bubbles expand and explode violently, throwing fragments of hot rock into the air. These fragments are cool as they fall back to Earth and form volcanic rocks. Plutonic rocks are formed when magma slowly cools inside the Earth’s crust. The process of slow cooling allows crystals to grow large enough that they can be seen with the naked eye. This is why plutonic rocks have a crystalline texture.
