1. Folds: These are wave-like bends in rock layers. They are caused by compressional forces, pushing the rock layers together. Folds can be symmetrical (both sides of the bend are equal) or asymmetrical (one side of the bend is steeper than the other).

2. Faults: These are fractures in the rock where there has been movement. They are caused by tensional (pulling apart), compressional (pushing together), or shear (sliding past each other) forces. Faults can be large or small, and they can cause earthquakes.

3. Joints: These are fractures in the rock where there has been no movement. They are caused by a variety of factors, such as cooling and contraction of the rock or stress from tectonic plates. Joints are often filled with minerals, which can create beautiful patterns in the rock.