Download Name___________________________ Date: Plate Tectonics

Name_________________________________________________
Date: ________________________
Plate Tectonics Worksheet
1. Divergent
2. Convergent
3. Transform
4. In your own words, state the theory of plate tectonics?
The theory that explains how large pieces of Earth's outermost layer, called tectonic plates, move and
change shape
5. Describe what happens when two plates carrying oceanic crust collide.
When two oceanic crust collide, one plate is subducted (the more dense, usually the older crust)
6. Describe what happens when two plates carrying continental crust collide
When two continental plates collide, they buckle and thicken, which pushes continental crust upward
creating mountain ranges.
7. Describe what happens when a plate carrying oceanic crust collides with a plate carrying continental crust.
When an oceanic crust collides with a continental crust, the ocean crust sinks (subducts) because it is
thinner and more dense.
8. What happens along a subduction zone?
Subduction zones occur at a convergent boundary between an oceanic plate and continental plate. The
more dense oceanic crust sinks.
9. What do most scientists believe is the driving force behind plate tectonics?
Convection currents
10. How do convection currents work (how they move the tectonic plates)?
Hot rock (expands) from deep within the Earth rises, but cooler rock near the surface sinks, Convection
causes the oceanic lithosphere to move sideways and away from the mid-ocean ridge.
11. List 2 features that form along a convergent boundary.
Ocean/ocean = trench
Ocean/continent = trench
Continent/continent = mountain
12. List 2 features that form along a divergent boundary.
Ocean/Ocean = ridge
Continent/continent = rift valley
13. What is a transform boundary?
Plate boundary where two plates slip past each other, in opposite directions.
14. What is the only feature of transform boundaries?
Fault
15. What is a fault?
Breaks in Earth’s crust where rocks have slipped past each other at a transform boundary.
16. The San Andreas Fault in California is an example of what type of boundary?
Transform
17. Along which type of boundary does subduction occur?
Convergent
18. Where do most earthquakes occur?
Transform
19. What type of boundary creates new oceanic crust?
Ocean/ocean divergent
20. What type of boundary destroys oceanic crust?
Continent/ocean convergent
21. What type of boundary neither creates nor destroys oceanic crust?
Transform
22. Explain what force caused the movement of the continents from one supercontinent to their present
positions.
Sea-floor spreading = when two oceanic plates separate from each other, magma from the mantle rises
to create a ridge. As new ocean floor is created it pushes the older rock away from the ridge pushing
the continents away from one another.
23.The lithosphere is broken into separate sections called ___plates__.
24. A(n) _rift valley__ is a deep valley on land that forms along a divergent boundary.
25. The geological theory that states that pieces of Earth’s crust are in constant, slow motion is called
_continental drift____.