1. Two plates carrying oceanic crust collide — One plate is forced beneath the other in a process called subduction, often forming deep ocean trenches and volcanic island arcs.
2. Two plates carrying continental crust collide — Neither plate is easily subducted; instead, they crumple and thicken, forming massive mountain ranges like the Himalayas.
3. A plate carrying oceanic crust collides with a plate carrying continental crust — The denser oceanic plate is subducted beneath the less dense continental plate, forming coastal mountain ranges and volcanic activity.
5. The movement of continents from one supercontinent to their present positions was caused by convection currents in the Earth’s mantle, which slowly drag the tectonic plates across the globe over millions of years.
6. A scientific theory is a well-tested concept that explains a wide range of observations.
7. Breaks in Earth’s crust where rocks have slipped past each other are called faults.
8. The lithosphere is broken into separate sections called plates.
9. A rift valley is a deep valley or landform that forms along a divergent boundary.
10. The geological theory that states that pieces of Earth’s crust are in constant, slow motion is called plate tectonics.
Parent Tip: Review the logic above to help your child master the concept of plate boundaries worksheet.
