what type of igneous rock makes up most oft...

Most of Earth’s crust is made of basalt , a dark, fine-grained mafic igneous rock that forms from rapidly cooled lava at or near the surface.

Quick Scoop: The Igneous Rock That Dominates Earth

• Basalt is the most common volcanic (extrusive) igneous rock on Earth’s surface, forming much of the ocean floor and many volcanic regions.

• It is mafic, meaning it is rich in magnesium and iron and relatively low in silica.

• In contrast, granite is the most common intrusive (plutonic) igneous rock, but it makes up continental crust at depth rather than “most” of the crust overall.

So if the question is “what type of igneous rock makes up most of the Earth’s crust (especially oceanic crust)?”, the answer is basalt.

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