Earth'S Crust Worksheet (Page 2 of 2) in pdf

Continental crust is almost always much older than oceanic crust. Because continental crust is rarely destroyed and recycled in

the process of subduction, some sections of continental crust are nearly as old as the Earth itself.

Clarifying Questions

1. What are the three layers of earth? _______________________________________________________________

2. Describe the layers of earth.

a. crust: _________________________________________________________________________________

b. mantle: _______________________________________________________________________________

c. core: __________________________________________________________________________________

3. What is the lithosphere? ________________________________________________________________________

_______________________________________________________________________________________________

4. What is the Mohorovicic discontinuity or the Moho? _________________________________________________

_______________________________________________________________________________________________

5. Earth crust is divided into two types: _____________________________and______________________________

6. What is the Conrad discontinuity? ________________________________________________________________

_______________________________________________________________________________________________

7. What are the most abundant rocks and minerals in both oceanic and continental crust?

_______________________________________________________________________________________________

8. How thick and dense is the oceanic crust?

_______________________________________________________________________________________________

9. New oceanic crust are constantly formed at the _______________________ of the __________________ ocean.

10. The tectonic plates at the mid ocean ridges are _________________________ or ________________________.

11. Which rocks are younger the one closer to the mid ocean ridge or the one farther from the mid ocean ridge?

Think! ______________________________________________________________________________________

12. New oceanic crust is created at the _________________________ and destroyed ________________________.

13. What is subduction? __________________________________________________________________________

_______________________________________________________________________________________________

14. In a convergent boundary, the __________________________ always subducts beneath the continental plate.

15. Juan de Fuca plate is a ___________________________ plate. In the Northwestern United States, Juan de Fuca

sunducts beneath the _________________________________________________________________________.

16. What happens to the lithosphere that subducts into the mantle?

______________________________________________________________________________________________.

17. How does subduction results to the recycling of rocks? Think!

_______________________________________________________________________________________________

18. Why is the oceanic crust much younger than the continental crust? _____________________________________

_______________________________________________________________________________________________

19. Oceanic crust are made mostly of ______________ while continental crust are mostly made of ______________

20. What is orogeny? _____________________________________________________________________________

_______________________________________________________________________________________________

21. What are the thickest parts of the continental crust?

_______________________________________________________________________________________________

22. Why is the continental crust almost always much older than the oceanic crust?Think!______________________

_______________________________________________________________________________________________

R. Angat

Earth'S Crust Worksheet Page 2