There are several ways that mountains can form, including through fault-block formation, folding, uplifting, and volcanic activity. Fault-block mountains are formed when huge tilted rock blocks are separated by faults. Folded mountains are created by compression forces that fold rock layers. Uplifted mountains occur when forces push up the earth's crust, allowing sedimentary rock to erode and leaving igneous or metamorphic rock exposed. Volcanic mountains are cone-shaped features composed of layered lava.

2. Folded Mountains

6. Fault-Block

10. Volcanic

14. Unwarped

16. Underwater

21. Trench/Rift