what are fold mountains

Fold mountains are mountains that are formed by the effects of folding on layers within the upper part of the Earths crust. They are created when two or more of Earths tectonic plates are pushed together, often at regions known as convergent plate boundaries. When plates and the continents riding on them collide or undergo subduction, the accumulated layers of rock may crumple and fold like a tablecloth that is pushed across a table, particularly if there is a mechanically weak layer such as salt. The folding effect is more profound in regions where the crust has a weak layer such as that made up of salt. Fold mountains are usually formed from sedimentary rocks which accumulated along the margins of continents. They are characterized by their arcuate shape whereby the mountains’ length greatly exceeds the width. Severely folded and faulted rocks are called nappes, and in asymmetric folding, there may also be recumbent and overturned folds. Some examples of fold mountains include the Jura Mountains and the Zagros Mountains.