WHAT HAPPENS WHEN PIECES OF THE CRUST ARE FORCED TOGETHER ?

1. WHAT HAPPENS WHEN PIECES OF THE CRUST ARE FORCED TOGETHER ?

2. Extension and injection of mantle material into crust Extension and injection of mantle material into crust

3. Crustal Compression Extension and injection of mantle material into crust Extension and injection of mantle material into crust

4. Crustal Compression Extension and injection of mantle material into crust Extension and injection of mantle material into crust ? Mass leaving Mantle Injected to Crust. Mass leaving Mantle Injected to Crust. Unless Crustal material is returned mantle in equal volume the Earth will grow larger and larger, but also “hollower” and “hollower”. Consideration of Conservation of Mass:

5. CRUSTAL COMPRESSION

6. CRUSTAL COMPRESSION Crustal Thickening

7. CRUSTAL COMPRESSION Crustal Thickening

8. CRUSTAL COMPRESSION Crustal Thickening Crustal Faulting

9. Crustal Convergence and Compression. Heat Heat and Pressure Denser Crust to Mantle.

10. CRUSTAL ROCKS Two Origins of Crustal Rocks: Continental Crust – Lower density as “floated” to outside of Earth. Oceanic Crust – Higher density as origin deeper in the mantle. Block 2 Block 1 Continental Crust Continental Crust Oceanic Crust

11. CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America

12. CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America 2. Oceanic vs. Oceanic: e.g. Japanese Islands

13. CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America 2. Oceanic vs. Oceanic: e.g. Japanese Islands 3. Continental vs. Continental: e.g. Himalayas

14. 1. GENERAL SETTING

15. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean

16. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Mid- Atlantic Ridge

17. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Mid- Atlantic Ridge

18. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Mid- Atlantic Ridge South American Plate African Plate

19. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Mid- Atlantic Ridge South American Plate African Plate

20. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean East Pacific Rise Mid- Atlantic Ridge South American Plate African Plate

21. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate Nazca Plate South American Plate African Plate

22. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate Nazca Plate South American Plate African Plate

23. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean CONVERGENCE AND CRUSTAL COMPRESSION East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate Nazca Plate South American Plate African Plate

24. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Crustal Thickening East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate South American Plate African Plate

25. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Compressional Faulting MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate South American Plate African Plate

26. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean More dense oceanic crust Sub-ducted beneath South America MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate South American Plate African Plate

27. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Deep ocean trench MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Mid- Atlantic Ridge Pacific Plate Nazca Plate South American Plate African Plate

28. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Shallow Earthquakes Deep Earthquakes MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Mid- Atlantic Ridge Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate

29. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Ocean sediments MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Mid- Atlantic Ridge Andes Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate

30. WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Andes MatoGrosso Brazilian Highlands Guiana Highlands East Pacific Rise Active Volcanoes Mid- Atlantic Ridge Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate

31. 03.05.b1

32. 03.09.a1

33. 2. JAPANESE ISLANDS GENERAL SETTING

34. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean

35. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise

36. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate

37. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate

38. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

39. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

40. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean CONVERGENCE AND CRUSTAL COMPRESSION East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

41. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean The Pacific Plate composed entirely of denser oceanic crust, is subducted beneath the oceanic fringe of the dominantly continental Eurasian Plate. East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

42. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Ocean trench East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

43. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Heat and Pressure cause melting Eurasian Plate Pacific Plate Nazca Plate

44. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Shallow and deep earthquakes East Pacific Rise Heat and Pressure cause melting Eurasian Plate Pacific Plate Nazca Plate

45. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Mountain building breaking ocean surface as a series of islands or “island arcs”. East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

46. JAPANESE ISLANDS Asia Sea of Japan Compressional faulting permits “recycled” oceanic crust to rise to the surface, producing active volcanoes. Pacific Ocean East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate

47. DO IT YOURSELF ISLAND ARCS! • TAKE A FLAT SHEET OF PAPER OR A PAGE FROM YOUR NOTEBOOK – SURFACE PLATE LIKE THE PACIFIC. • MAKE A SEMI-CIRCLE WITH YOUR THUMB AND INDEX FINGER ON ONE HAND AND THE DESK – THE SMALLER SPACE IN THE INTERIOR OF THE EARTH AS THE RADIUS DIMINISHES. • TRY TO PUSH THE PAPER THROUGH THE RESTRICTED SEMI-CIRCLE WITHOUTH CREASING IT. • WHAT HAPPENS TO THE SHAPE FORMED BY YOUR “FLAT” PIECE OF PAPER? • IF SEDIMENT WAS SCRAPED OFF THE TOP OF THAT PAPER, WHAT SHAPE WOULD THE ACCUMULATED SEDIMENTS DESCRIBE?

48. Island Arcs Ocean Trenches

49. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean As the Pacific plate is subducted it tends to “roll-back” southeastwards, pulling the Japanese Islands further off of Asia. East Pacific Rise “Push” “Pull” Eurasian Plate Pacific Plate Nazca Plate

50. JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Motion of Japanese islands away from Asia causes split of crust and “back arc spreading” beneath the sea of Japan . East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate