Intrusions,+Faults,+and+Unconformities

Intrusions are masses of hardened magma that have pushed into others bodies of rock. Intrusions are always younger than the rock layers around and beneth it.

Faults are breaks in rock layers. Faults are always younger than the rock it cuts through.

An unconformity occurs where erosion wears away layers of rock and others layers of rock form above it. Unconformities can cause gaps in the geologic record.

Is the intrusion or fault younger? Look at the unconformity between A and B, the fault, and the intrusion. Is the intrusion or the fault younger? Which is the youngest of the three and which is the oldest? Which is older, A or F? Can a younger rock be below an older rock?

Is the unconformity, fault, or intrusion younger?

Which is younger the unconformity between A & B or the intrusion E? Which is younger the unconformity between A & B or the fault F?

Rock Maps below by Jason Schmit