The Earth's crust is the outermost layer of our planet, a solid and rocky shell that forms the foundation for all life and geological processes. It's composed of two distinct types: continental crust and oceanic crust.
Continental Crust:
- Less dense: It's lighter than oceanic crust, allowing it to float higher on the mantle.
- Older: It's generally older than oceanic crust, with some parts dating back billions of years.
- Granite and quartz rich: Primarily composed of granitic rocks, rich in silicon and oxygen.
- Thicker: On average, it's thicker than oceanic crust, ranging from 30 to 70 kilometers.
Oceanic Crust:
- Denser: It's denser than continental crust, causing it to sit lower on the mantle.
- Younger: It's constantly being created and destroyed through plate tectonics, making it relatively young.
- Basaltic rocks: Primarily composed of basaltic rocks like gabbro, which are dark and rich in iron and magnesium.
- Thinner: It's thinner than continental crust, typically around 5 to 10 kilometers thick.
Overall, the Earth's crust is a dynamic and complex layer that plays a crucial role in shaping our planet's surface. It's constantly changing through geological processes like plate tectonics, volcanic activity, and erosion.
