Volcanic mountains are mountains that form when molten rock erupts onto the earth's surface. They can either form on land or in the ocean. The Cascade Range in Washington, Oregon and northern California is composed of volcanic mountains. Some of the largest volcanic mountains are found along divergent boundaries, which form the mid-ocean ridges. The mid-ocean ridges have huge volcanic mountain chains that run through the Atlantic, Pacific and Indian Oceans. The mountains in the mid-ocean ridges can actually grow tall enough to create islands such as Iceland or the Azores. Other volcanic mountains can form over hot spots, which are pockets of magma beneath the crust that erupt onto earth's surface. The Hawaiian Islands are actually the tops of really high volcanic islands that have formed over a hot spot on the sea floor. The main Hawiian island is actually a volcano that is about 9 km above the ocean floor, with a base that is about 160 km wide. Almost 4 km of this island is above sea level. Folded mountains
Folded mountains make up some of the highest mountains in the world. Folded mountains commonly form along boundaries, where 2 continents are colliding. They tend to look like an accordion. Some really complex folds can be found in parts of the Alps, Himalayas, Appalachians, and Russia's Ural Mountains. These long mountain chains also show extensive signs of folding. block mountains
block mountains are formed when parts of the earth's crust has been broken off into large block mountains are formed when two simultaneous blocks of land rise above or fall down leaving its middle part behind, when magma pushes up and forces top layers of rock (elastic) up with it. An example is the Flinders Ranges in South Australia. Domed mountains, although have broken (plasic) and move up as a 'chunk'.A fault block mountain is a mountain or range formed as a horst when it was elevated between parallel normal faults. A horst is the raised fault block bounded by normal faults.