1. HISTORY OF THE CONTINENTS
Grotzinger • Jordan
Understanding Earth
Seventh Edition
Chapter 10:
HISTORY OF THE CONTINENTS
© 2014 by W. H. Freeman and Company

2. History of the Continents
Chapter 10:
History of the Continents

3. About Evolution of the Continents
Nearly two-thirds of the Earth’s surface – all of the oceanic crust – was formed over the past 200 million years.
However, rocks of the continents are much older, as old as 4 billion years.
Studying the continents tells us how the continental lithosphere formed and evolved.

4. Lecture Outline The structure of North America
2. Tectonic provinces around the world
3. How continents grow
4. How continents are modified
5. Origin of cratons
6. Deep structure of the continents

5. ● The stable interior ● Canadian shield ● interior platform
The Structure of North America
● The stable interior
● Canadian shield
● interior platform
● basins and uplifts

8. The Structure of North America
● The Appalachian fold belt
● Valley and ridge province
● Blue ridge province
● Piedmont
● Coastal Plain & Continental Shelf

11. ● The North American cordillera ● uplift and orogeny ● rejuvenation
The Structure of North America
● The North American cordillera
● uplift and orogeny
● rejuvenation
● crustal stretching

13. ● Continental geology ● cratons ● orogens ● passive margins
2. Tectonic Provinces
around the World
● Continental geology
● cratons
● orogens
● passive margins
● active margins

14. ● Types of tectonic provinces ● shield ● platform ● continental basin
around the World
● Types of tectonic provinces
● shield
● platform
● continental basin
● orogen
● extended crust

16. ● Ages of tectonic provinces ● Archean ● Early Proterozoic
around the World
● Ages of tectonic provinces
● Archean
● Early Proterozoic
● Middle Proterozoic
● Late Proterozoic
● Paleozoic
● Mesozoic and Cenozoic

18. Thought questions for this chapter
Figure 10.8b shows more continental crust of Mesozoic-Cenozoic tectonic age than continental crust of any geologic period. Does this contradict the hypothesis that most of the continental crust was differentiated from the mantle in the first half of Earth’s history?

19. ● Continental accretion ● accreted terrains ● exotic terrains
3. How Continents Grow
● Modes of growth
● Magmatic addition
● Continental accretion
● accreted terrains
● exotic terrains

22. Terrain
accretion

23. Terrain accretion Spreading center (divergent boundary)
Aleutian
Trench
Wrangellia
Spreading center
(divergent boundary)
Subduction margin
(convergent boundary)
Cascadia
Trench
Transform
fault
N O R T H
A M E R I C A
San Andreas
Fault
Island arc
Submarine deposits
Ancient ocean floor
Displaced continental
fragments

24. Thought questions for this chapter
How would you recognize an accreted terrain? How could you tell if it originated far away or nearby?

25. ● Modification by plate collision ● Alpine-Himalayan orogeny
4. How Continents Are Modified
● Modification by plate collision
● Alpine-Himalayan orogeny
● Assembly of Pangaea
● The Wilson Cycle

26. Alpine-Himalayan Orogeny

27. Alpine-Himalayan Orogeny

28. Alpine-Himalayan Orogeny

29. Alpine-Himalayan Orogeny

30. Alpine-Himalayan Orogeny

38. Wilson
Cycle

39. Geologic Time Scale of Events in the History of Earth’s Continents

40. ● Modification by epeirogeny ● cooling and heating of lithosphere
4. How Continents Are Modified
● Modification by epeirogeny
● cooling and heating of lithosphere
● weight of accumulating sediments or glacial ice

46. Thought questions for this chapter
How would you identify a region where active orogeny is taking place today? Give an example.
Would you prefer to live on a planet with orogenies or without them? Why?

47. ● granite-greenstone terrains
5. Origin of Cratons
● Archean cratons
● granite-greenstone terrains
● high-grade metamorphic terrains

49. Thought questions for this chapter
Why are the ocean basins just about the right size to contain all the water on Earth’s surface?

50. ● Structure of the craton ● continental crust ● cratonic keel
6. Deep Structure of the Continents
● Structure of the craton
● continental crust
● cratonic keel

52. Thought questions for this chapter
What would happen at the surface if the cold keel beneath a craton suddenly heated up? How might this effect be related to the formation of the Colorado Plateau?

53. Key terms and concepts Accretion Active margin Craton Cratonic keel
Accreted terrain
Accretion
Active margin
Craton
Cratonic keel
Epeirogeny
Glacial rebound
Magmatic addition
Orogen
Orogeny
Passive margin
Rejuvenation
Shield
Tectonic age

54. Key terms and concepts
Tectonic province
Wilson cycle