Wegener proposes continental drift, noting coastlines and fossils hint a once‑joined world.

Coastlines, rock layers, and identical fossils across oceans suggest a shattered supercontinent.

Mid-ocean ridges and magnetic stripes reveal new crust forming and moving apart from the center.

The lithosphere splits into plates riding atop the asthenosphere, reshaping Earth’s surface.

Divergent, convergent, and transform margins craft landforms and seismic risks.