text: Well there are these things called tectonic plates in the earth's crust. They are constantly being moved by the magma in the mantle. Sometimes two of these plates collide. Now the two plates can do one of three things:\n1) create faults : faults are when the two plates are grinding past each other in opposite directions. Sometimes the tension there can cause earthquakes.(San Andreas Fault)\n\n2)Fold: when the two plates are moving toward each other and are the same weight they fold upwards and create ridges like mountains (Himalayan mts)\n\n3) subduction: if one of the two plates is less weight than the other the one with the lesser weight sinks below the other and eventually melts into magma. ( Ring of Fire)