How Are Mountains Formed?

When two of the gigantic tectonic plates that form this earth's surface push against each other something has to give. Sometimes the land cracks and we get what would be called a volcano. Other times the land is lifted and falls back to fold over itself creating ridges; these ridges form mountains. Plates can also stretch until they begin to crack and slide into each other. This forms fault-block mountains.

Another type of formation is a fold mountain which is made up of numerous layers of rocks that are squeezed together to create folds. This explains how fossils of marine animals have sometimes been found on the peaks of fold mountains. Underwater, in the ocean, huge mountains are formed in this way as well as when plates spread away form one another releasing magma through the gap. The magma cools into rock very quickly as it interacts with the cool ocean water.

Mountains get their unique and often beautiful shapes from erosion. Frozen glaciers can carve magnificent gorges between two mountain ridges as it slides slowly by. This is how U shaped valleys, rounded bowls, and sharp horns are formed. Rain, ice, and wind are some of the main causes of erosion. Water seeps into the cracks of the mountains surface and pushes it apart. At the same time minerals are dissolved and carried off with excess moisture. Rivers can carve immense mountains into huge canyons, like the Grand Canyon.

The Grand Canyon was carved by the Colorado river; at its deepest the canyon is six thousand vertical feet deep and can be eighteen miles wide in some places After enough time has passed these cracks widen enough for large portions of the mountain to fall and break into smaller pieces (boulders.) In most cases, after millions of years have passed, the mountains will erode away to become low rounded hills. The debris caused by the erosion will become the sand, soil, and sediment in nearby ecosystems.