What does extrusive mean in rocks?

What does extrusive mean in rocks?

Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

What does extrusive mean in geography?

Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. Other examples of extrusive rocks are rhyolite and andesite.

What rocks are extrusive?

Types of extrusive igneous rocks include: pumice, obsidian, andesite, rhyolite, and basalt.

What are 4 extrusive rocks?

Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.

How extrusive rocks are formed?

Extrusive Igneous Rocks: Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures.

What do you mean by extrusive landforms?

Extrusive igneous landforms are the result of magma coming from deep within the earth to the surface, where it cools as lava. Volcanic processes are constantly changing the Earth. Eruptions can create new islands, build and destroy mountains, and alter landscapes.

What does the word extrusive mean?

: relating to or formed by geologic extrusion from the earth in a molten state or as volcanic ash.

Is andesite an extrusive rock?

Andesite is an extrusive rock intermediate in composition between rhyolite and basalt. Andesite lava is of moderate viscosity and forms thick lava flows and domes. The word andesite is derived from the Andes Mountains in South America, where andesite is common. Andesite is the volcanic equivalent of diorite.

What are extrusive volcanic landforms?

Extrusive landforms are formed from material thrown out to the surface during volcanic activity. The materials thrown out include lava flows, pyroclastic debris, volcanic bombs, ash, dust and gases such as nitrogen compounds, sulphur compounds and minor amounts of chlorine, hydrogen and argon.

Where do you find extrusive rocks?

Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures.

How are extrusive landforms formed?

What does extrusive mean?

Definition of extrusive. : relating to or formed by geological extrusion from the earth in a molten state or as volcanic ash.

What is intrusive and extrusive?

• Intrusive rocks are formed from magma whereas extrusive rocks are formed from lava. • Intrusive rocks are formed deep inside the surface of the earth whereas extrusive rocks are formed at the surface of the earth when magma finds a way to eject or pour out of the surface.

How are extrusive and intrusive rocks formed?

Extrusive rocks and intrusive rocks both form when hot molten material crystallizes. However, extrusive rocks form from lava at the surface of the Earth, whereas intrusive rocks form from magma underground, often relatively deep in the Earth. A pluton is a block of intrusive igneous rock.

Is gabbro an extrusive or intrusive rock?

Gabbro is a coarse-grained and usually dark-colored igneous rock. It is an intrusive rock. It means that it formed as magma cooled slowly in the crust. Igneous rocks with similar composition are basalt (extrusive equivalent of gabbro) and diabase (the same rock type could be named dolerite or microgabbro instead).