Evidence About Earth’s Past (Book)

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RELATIVE AGE OF ROCKS

- Cross-Cutting Relationships

Rock layers may have another rock cutting across them, like the igneous rock in Figure. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them.

Cross-cutting relationships in rock layers

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Cross-cutting relationships in rock layers.
Rock D is a dike that cuts across all the other rocks. Is it older or younger than the other rocks?