Plate boundaries

Plate tectonics connects scenery that otherwise seems unrelated: mountain belts, volcanic arcs, deep ocean trenches and rift landscapes. The process operates on a scale much larger than a visitor's viewpoint, and its effects accumulate over long periods.

At a convergent boundary, one plate may descend beneath another, or continental crust may collide and thicken. At a divergent boundary, plates move apart. At a transform boundary, motion is largely sideways. These are broad models; actual regions have complicated histories and do not fit into a single tidy drawing.

A good travel question is therefore not simply whether a place is volcanic or mountainous, but how its regional setting helps explain that character. Local geological interpretation can connect the spectacular feature to the larger Earth system.

Further explanation and context: www.nps.gov. The examples below are editorial connections, not a claim that every place has an identical history or form.