Geologic History: Relative Dating

interactive Multiple Choice: Cross-Cutting Relations

Image of rock layers labeled 1-8 with layer 1 on the bottom. Image also includes Dikes A, B and C. Dike C cuts from the bottom to the top at a slight diagonal across layers 1-8. Dike B cuts horizontally at a slight angle through layers 4-6 and through Dike C. Dike A cuts diagonally from the lower left to the upper right through layers 1-8 and through Dike B.

Here is a more difficult example of how cross-cutting relations can be used to assign relative ages to rock layers and events. Now that you have learned about some principles of relative dating, study the image and see if you can answer the questions that follow. You can use any principle of relative dating you have learned about so far.

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