Explain the differences between the continental and oceanic crust.

The Earth's crust is divided into two main types: continental crust and oceanic crust. These two types of crust differ in terms of composition, thickness, density, age, and geological features.

1. Composition: The continental crust is primarily composed of granitic rocks, which are rich in silica and aluminum. It is less dense compared to the oceanic crust. On the other hand, the oceanic crust is mainly composed of basaltic rocks, which are rich in iron and magnesium.

2. Thickness: The continental crust is significantly thicker than the oceanic crust. It ranges from 30 to 50 kilometers in thickness, while the oceanic crust is relatively thinner, ranging from 5 to 10 kilometers.

3. Density: Due to differences in composition, the continental crust has a lower density compared to the oceanic crust. The average density of the continental crust is around 2.7 grams per cubic centimeter, while the oceanic crust has an average density of about 3 grams per cubic centimeter.

4. Age: The continental crust is generally older than the oceanic crust. Some parts of the continental crust date back to over 4 billion years, while the oceanic crust is relatively young, with the oldest parts being around 200 million years old.

5. Geological Features: The continental crust is characterized by diverse geological features such as mountains, plateaus, and deep sedimentary basins. It also contains large amounts of mineral resources. In contrast, the oceanic crust is relatively flat and features underwater mountain ranges known as mid-ocean ridges, deep-sea trenches, and volcanic islands.

6. Tectonic Activity: The continental crust is involved in various tectonic activities, including the collision of tectonic plates, resulting in the formation of mountain ranges and earthquakes. The oceanic crust is more active in terms of volcanic activity and the creation of new crust at mid-ocean ridges.

In summary, the continental crust and oceanic crust differ in terms of composition, thickness, density, age, geological features, and tectonic activity. These differences contribute to the distinct characteristics and behaviors of these two types of crust on Earth.