Both these mountain ranges are still getting higher today as the collisions continue. These collisions are accompanied by lots of fault movements which cause earthquakes. The pressures and temperatures caused by the collision change the sediments into what we call metamorphic rocks. Marble is a common metamorphic rock, formed by compressing and heating limestone, a sedimentary rock. The other kind of rocks that occur on the crust are the igneous rocks - formed from molten rock.
Molten rock can rise up from the mantle into the crust and cool slowly forming big crystals.
Granite is an example of this kind of rock. If the molten rock reaches the surface and pours out it can form a volcano. The rocks cool quickly and form smaller crystals. A typical rock like this is basalt. Igneous activity commonly takes place at the edges of the plates as well.