Where plates collide

Part of Hall of Planet Earth.

Plate Colliding Model AMNH/R.Mickens

The most geologically active regions on Earth are where plates collide. When two oceanic plates converge, the cooler, denser one descends, or subducts, beneath the overriding plate and sinks into the mantle. When an oceanic plate meets a plate with a continent riding atop it, the oceanic plate is again subducted. When two continents meet, one is thrust over the other, and great mountain ranges like the Himalayas are formed.