Question

which characteristic is shared by intrusions and faults?
all are cracks.
all are igneous rocks.
all cause gaps in the geologic record.
all are younger than surrounding rocks.

Explanation:

According to the principle of cross - cutting relationships in geology, both intrusions (igneous rock bodies that form by cooling and solidifying below the Earth's surface) and faults (fractures in the Earth's crust along which movement has occurred) are younger than the rocks they cut through. Intrusions are not cracks (A is wrong), not all are igneous rocks (faults aren't igneous rocks, B is wrong), and they don't all cause gaps in the geologic record (C is wrong).

Answer:

D. All are younger than surrounding rocks.