Plate Tectonics

Plates move apart at 

• Transform boundaries
• convergent boundaries
• divergent boundaries
• convection boundaries

Who proposed the theory of seafloor spreading?

• Harry Hess
• Alfred Wegener
• Carl Sagan
• TC Chamberlin

Why does continental drift occur

• pangaea
• magnetic reversal
• earthquakes
• seafloor spreading

The cycle of heating, rising, cooling, and sinking is called

• convection current
• transform boundary
• subduction zone
• strike-slip faults

Plates collide at 

• divergent boundaries
• convergent boundaries
• lithosphere
• subduction 

Oceanic plates are pushed down into the upper mantle in 

• convergent boundary
• subduction zone
• convection current
• continental drift

Plate movement can be seen at 

• plate centers
• continent boundaries
• plate boundaries
• pangaea

Theory that Earth's crust is split into pieces

• plate tectonics 
• seafloor spreading
• pangaea
• lithosphere

What is the rigid part of plates

• asthenosphere 
• convection currents
• plate tectonics 
• lithosphere

Earth's plasticlike layer

• plate tectonics 
• continental drift
• lithosphere
• asthenosphere