Question

Which characteristic is shared by extrusions, intrusions, and faults?

Answer 1

By extrusion, intrusion and fault, the age of the rock layers are determined.  

When magma cools on the surface of the Earth is known as an extrusion. Extrusions are always younger than the rock it is sitting on. When magma cools beneath the surface of the Earth it’s called an intrusion. Intrusions are always younger than the rocks around it. A break in the Earth’s crust is called fault. A fault is always younger than the rock it cuts through.