What is the mantle made of?

  • Exhibition Text

    • We know the composition of the uppermost mantle because we have samples of it. There are no known samples from the lower mantle. The only way to determine its mineralogy and structure is to observe the speed of seismic waves, and to re-create deep-mantle conditions in the laboratory.

      As depth increases, the minerals that make up the mantle become more dense, or compact. For example, the common mineral olivine changes to the more compact structural forms of spinel and then perovskite.

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  • For Educators

    • Topic: Earth Science

      Subtopic: Earth Structure

      Keywords: Geology, Stratigraphic, density, Rocks, Earth (Planet)--Mantle, Seismology

      Audience: General

In This Section

Mantle xenolith

Mantle xenolith

Fragments from the upper mantle are sometimes transported to the surface by erupting lava.



Kimberlite is a relatively rare type of lava. It comes from depths as great as 300 to 350 kilometers.