Mantle heat may have boosted Earth's crust 3 billion years ago

Little is known about the nature and evolution of Earth's continental crust before a few billion years ago because cratons, or stable swaths of the lithosphere more than 2–3 billion years old, are relatively rare.

Managing meandering waterways in a changing world

Just as water moves through a river, rivers themselves move across the landscape. They carve valleys and canyons, create floodplains and deltas, and transport sediment from the uplands to the ocean.

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