Describe the composition and relative density of continental crust compared to oceanic crust.

Continental crust is felsic (rich in silica) and less dense, while oceanic crust is mafic (rich in iron and magnesium) and more dense.

Explain the process of subduction and why it occurs.

Subduction is when the denser oceanic crust slides beneath the less dense continental crust due to density differences.

The mantle, composed primarily of peridotite.

The mantle convects due to heat transfer, causing mid-ocean ridges and rift zones at upwelling areas and subduction zones at sinking areas.

Grade 8th Grade · Science · 45 min

I can describe the characteristics of Earth's layers.

Professor Dave Explains · 10:08

An Overview of Earth’s Layers

3 key concepts

1
The Earth's crust is divided into two types: continental crust, which is felsic and thick, and oceanic crust, which is mafic and thin.
2
The mantle is a solid but malleable layer mainly composed of peridotite, and it convects, transferring heat to the surface.
3
Earth's magnetic field is generated by the geodynamo in the liquid outer core, and the solid inner core helps stabilize this field.

7 questions · Multiple choice & Short answer

Quick comprehension check

“Describe two differences between oceanic crust and continental crust.”

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