Folds are formed when compressed rock deforms but unlike faults, it does not crack. Folding normally takes place on the boundary between two converging plates. Mountains usually start as sedimentary rock on the bottom of the sea. This is then squashed upwards by converging continental plates. It then got folded, faulted, metamorphosed, and intruded by igneous plutons.
Underwater volcanoes erupt a lot at diverging boundaries.
The water is superheated and causes melting and a volcano occurs. Continental drift Alfred Wegener suggested that around 200 million years ago, all the continents were joined together to form one super-continent. He called the super-continent Pangaea. Then over millions of years this broke up and the continents moved apart. He called their movement continental drift.