By Richard I. Gibson
Continental crust contains most of the lighter elements in the solid earth, things like aluminum, silicon, and carbon. Continental crust is less dense than the basaltic oceanic crust, an a lot less dense than the mantle.
The continents are kind of like light blobs that forms on top of the iron and other dense stuff that mostly sank deeper into the earth. The separation of light and dense crust happened pretty early in the earth’s formation. We talked about that on January 2. And the blobs have been drifting around the surface ever since.
Map from U.S. Geological Survey.
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