Which crust forms the ocean floor and is thinner and more dense?

Which crust forms the ocean floor and is thinner and more dense?

• A. Continental Crust
• B. Oceanic Crust
• C. Mantle
• D. Inner Core

Answer: (B)

The ocean floor is formed by oceanic crust, which is thinner and more dense. Oceanic crust is composed largely of basalt and is only about 5–10 km thick, with a higher density (around 3.0 g/cm³). In contrast, continental crust is much thicker (roughly 35–70 km) and less dense (about 2.7 g/cm³) because it is granitic in composition. The mantle lies beneath the crust, and the inner core sits at Earth's center, so they aren’t crust. The higher density and thinner nature of oceanic crust explain why it forms the ocean basins and can subduct beneath lighter continental crust at tectonic boundaries.

The ocean floor is formed by oceanic crust, which is thinner and more dense. Oceanic crust is composed largely of basalt and is only about 5–10 km thick, with a higher density (around 3.0 g/cm³). In contrast, continental crust is much thicker (roughly 35–70 km) and less dense (about 2.7 g/cm³) because it is granitic in composition. The mantle lies beneath the crust, and the inner core sits at Earth's center, so they aren’t crust. The higher density and thinner nature of oceanic crust explain why it forms the ocean basins and can subduct beneath lighter continental crust at tectonic boundaries.