Which of the following describes the composition of oceanic crust?

The composition of oceanic crust is primarily basaltic rocks, which makes the correct answer to the question. Oceanic crust is formed at mid-ocean ridges through the process of seafloor spreading, where magma rises from the mantle and solidifies to create new oceanic crust. Basalt is a mafic rock rich in iron and magnesium, giving it a denser structure compared to continental crust.

Basaltic rocks are typically characterized by their dark coloration and fine-grained texture, resulting from the rapid cooling of lava at the ocean floor. This composition is consistent across the majority of the oceanic crust, which is different from the continental crust that is more varied in its geological makeup.

In contrast, sedimentary rocks, granitoid rocks, and limestone do not represent the predominant composition of oceanic crust. Sedimentary rocks are typically formed from the accumulation of sediments, which is not the case for the oceanic crust's formation. Granitoid rocks, such as granite, are found predominantly in continental crust due to their composition and formation through slow cooling of magma. Limestone, primarily composed of calcium carbonate, is often found in sedimentary basins but does not characterize oceanic crust's foundational makeup. Thus, basaltic rocks accurately reflect what