Igneous Textures
This texture forms when magma cools slowly underground?
What is phaneritic texture?
Rocks that form from lava cooling on Earth’s surface are called this.
What are extrusive rocks?
This composition is rich in magnesium and iron
What is mafic?
This dark, fine-grained igneous rock is commonly found in oceanic crust.
What is basalt?
This is molten rock found underground.
What is magma?
This texture forms from very rapid cooling on Earth’s surface, producing tiny crystals.
What is aphanitic?
Rocks that form from magma cooling underground are called this.
What are intrusive rocks?
This composition is rich in silica and forms lighter-colored rocks.
What is felsic?
This light-colored, coarse-grained igneous rock forms continental crust.
What is granite?
This is molten rock that reaches Earth’s surface.
What is lava?
This texture looks like glass because crystals do not have time to form.
What is glassy?
Intrusive rocks usually have this crystal size.
What is large or coarse-grained?
This composition is between mafic and felsic.
What is intermediate?
This glassy rock forms from very rapid cooling of lava.
What is obsidian?
This process describes the formation of crystals as magma cools.
What is crystallization?
This texture contains both large and small crystals in the same rock.
What is porphyritic?
Extrusive rocks usually have this crystal size.
What is small or fine-grained?
This mineral is common in mafic rocks and is dark green.
What is olivine?
This rock is light and full of holes due to gas bubbles.
What is pumice?
This process explains how magma forms from melting rocks.
What is partial melting?
This texture forms when gas bubbles are trapped in cooling lava, leaving holes.
What is vesicular?
This is the main reason intrusive rocks cool more slowly.
What is insulation from surrounding rock layers?
This mineral is common in felsic rocks and is light-colored and potassium-rich.
What is orthoclase feldspar?
This dark, coarse-grained rock is the intrusive equivalent of basalt.
What is gabbro?
This process occurs when magma rises because it is less dense than surrounding rock.
What is magma buoyancy?