Which of the following accurately describes the oceanic crust compared to the continental crust?

Which of the following accurately describes the oceanic crust compared to the continental crust?

• A. More buoyant
• B. More dense
• C. Less stable
• D. Thicker

Answer: (B)

The oceanic crust is indeed more dense than the continental crust. This higher density is primarily due to its composition, which contains more basaltic rocks that are denser than the granitic rocks typically found in the continental crust. Oceanic crust usually has a density of about 3.0 g/cm³ compared to the 2.7 g/cm³ of continental crust. This difference in density is crucial in understanding how these two types of crust interact at plate boundaries. For instance, when oceanic and continental plates converge, the denser oceanic crust is subducted beneath the lighter continental crust, leading to various geological phenomena such as the formation of deep ocean trenches and volcanic activity. In contrast, the other options lack accuracy when comparing the two crust types. For example, oceanic crust is generally less buoyant than continental crust and is not thicker; in fact, it is usually much thinner than continental crust. The stability of the oceanic crust versus the continental crust can vary and is context-dependent—while oceanic crust can be considered less stable as it is constantly being formed and destroyed at mid-ocean ridges and subduction zones, this is not a defining characteristic relative to density.

The oceanic crust is indeed more dense than the continental crust. This higher density is primarily due to its composition, which contains more basaltic rocks that are denser than the granitic rocks typically found in the continental crust. Oceanic crust usually has a density of about 3.0 g/cm³ compared to the 2.7 g/cm³ of continental crust.

This difference in density is crucial in understanding how these two types of crust interact at plate boundaries. For instance, when oceanic and continental plates converge, the denser oceanic crust is subducted beneath the lighter continental crust, leading to various geological phenomena such as the formation of deep ocean trenches and volcanic activity.

In contrast, the other options lack accuracy when comparing the two crust types. For example, oceanic crust is generally less buoyant than continental crust and is not thicker; in fact, it is usually much thinner than continental crust. The stability of the oceanic crust versus the continental crust can vary and is context-dependent—while oceanic crust can be considered less stable as it is constantly being formed and destroyed at mid-ocean ridges and subduction zones, this is not a defining characteristic relative to density.