Alfred Wegener's hypothesis that the continents were once joined together in a supercontinent named Pangea.

• seafloor spreading

• continental drift

• plate tectonics

• continental crust

Theory that states that Earth's surface is made of rigid slabs of rock that move with respect to each other.

• continental drift

• convection currents

• seafloor spreading

• plate tectonics

The process by which new oceanic crust forms along mid-ocean ridges.

• subduction

• seafloor spreading

• convection currents

• plate tectonics

The process that occurs when one tectonic plate moves under another tectonic plate.

• seafloor spreading

• convection currents

• continental drift

• subduction

Long, narrow mountain range on the ocean floor; formed by magma at divergent plate boundaries.

• mid-ocean ridge

• subduction

• convection currents

• plate tectonics

Material in the mantle constantly rises as it is heated becomes less dense and falls as it cools and becomes more dense.

• convergent boundary

• convection currents

• continental drift

• plate tectonics

Where is new lithosphere (crust) formed?

• subduction zones

• fold mountains

• mid-ocean ridges

• outer core

This type of boundary has tectonic plates that slide past each other and often cause earthquakes.

• Convergent

• Divergent

• Continental

• Transform

Where is old lithosphere (crust) returned to the mantle?

• mid-ocean ridges

• subduction zones

• convection currents

• volcanic mountains

The boundary between two plates that move away from each other.

• convergent

• divergent

• continental

• transform