Passage: Most of the world’s largest mountains form as plates collide at convergent plate boundaries. Continents are too buoyant to get pushed down into the mantle. So when the plates smash together, the crust crumples upwards. This creates mountains. Folding and faulting in these collision zones makes the crust thicker. Answer: buoyancy
Why are continents unable to be pushed down into the mantle by plate boundaries?