What is true about faults, folds, and intrusions?

The concept of age relationships between faults, folds, and intrusions and the rock layers they interact with is grounded in the principles of geological time and relative dating. In geology, when a fault or fold disrupts existing rock layers, it is generally understood that these deformations occur after the formation of the layers they disturb. Hence, faults and folds will be younger than the rocks they affect because they represent a later event in the geological history.

Similarly, intrusions, which involve molten material (magma) penetrating and solidifying within existing rock layers, also result in younger geological features. The intrusion of magma occurs after the surrounding rocks have formed, representing a more recent geological event.

This understanding is key to geological interpretation, enabling scientists to reconstruct the sequence of geological events and establish the relative ages of different rock formations.