Question #bc134

1 Answer
Julian M.
Feb 28, 2018

Intrusions are younger. Look for alteration of sedimentary rock from the hot intrusion. Also look for cross-cutting relationships.

Explanation:

The sedimentary layers would have to be in place BEFORE the igneous intrusion formed, otherwise the intrusion would have spilled out on the surface as a lava flow. Therefore, igneous intrusions are usually younger. Look for altered minerals in the sedimentary rock due to the hot intrusion. Also, younger intrusions will cross-cut older/existing layers.

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