Plate Tectonics

The theory of plate tectonics explains the movement of the Earth's lithosphere, which is divided into tectonic plates that float on the semi-fluid asthenosphere beneath them.

The three main types of plate boundaries are divergent boundaries, convergent boundaries, and transform boundaries.

A divergent boundary is where two tectonic plates move away from each other, often resulting in the formation of new crust, such as mid-ocean ridges.

A convergent boundary is where two tectonic plates move towards each other, leading to subduction or mountain building.

A transform boundary is where two tectonic plates slide past each other horizontally, causing earthquakes.

Evidence includes the fit of continental coastlines, fossil distribution, geological similarities across continents, and the presence of mid-ocean ridges.

Alfred Wegener proposed the hypothesis of continental drift.

Continental drift is the hypothesis that continents have moved over geological time and were once joined together in a supercontinent.

Subduction is the process where one tectonic plate moves under another and sinks into the mantle.

Mid-ocean ridges are significant as they are sites of new oceanic crust formation and are associated with divergent boundaries.