Which type of rock is predominantly found in oceanic crust?

The correct answer is basalt, as it is the primary type of rock that composes oceanic crust. Oceanic crust is relatively thin compared to continental crust and is formed from the solidification of magma that is rich in iron and magnesium. This magma cools and crystallizes to form basalt, which is a dark, fine-grained volcanic rock.

Basalt is formed at mid-ocean ridges, where tectonic plates are pulling apart and allowing magma to rise from the mantle and solidify to create new oceanic crust. Additionally, the physical properties of basalt—such as its density and composition—are well suited to the characteristics of the oceanic environment.

In contrast, granite is predominantly found in continental crust, as it is a lighter-colored, coarse-grained rock that forms from the slow crystallization of magma beneath the Earth's surface. Sandstone, being a sedimentary rock, is formed from the compaction of sand particles, and is typically associated with former beach or river environments, rather than oceanic crust. Gneiss, a metamorphic rock, is formed from the alteration of existing rocks under heat and pressure, usually found in continental areas rather than oceanic regions.

Thus, basalt's formation and the conditions of the oceanic