Theories and Plate Boundaries
by Sai Joya
1. Tibet,Himalayas
2. Pero-chile
3. Volcanic arc at the edge of the continent
4. Continental crust is too bouyant to subduct
5. Produces crust up to twice as thick as normal and a high mountain plateau (mountain ranges)
6. Pacific ring of fire
7. Himalayas (Nepal), Sierra Madre (Philippines
8. Pacific Ring of Fire is situated where the oceanic plate and several smaller micro-plates subducting along the Philippine plate, Philippine Trench, to the East and West.
9. epicenter of earthquakes are usually found along plate boundaries
10. Earthquake epicenter
11. Distribution of mountain ranges
12. Mountain ranges formed along convergence of continental plate boundaries
13. active volcanoes are located in the area where plate movement occurs
14. Distribution of active volcano
15. this is where subduction occurs. because of the cool denser it will subduct
16. Happens at spreading center where plates are moving apart.
17. Warmer material in the mantle moves down and cooler material in the mantle moves up.
18. Mantle Convection Currents
19. Caeses of tectonic plate movement
20. Distribution of active volcanoes,mountain ranges support the plate tectonic theory
21. Alfred Wegener
22. Marianas, Indonesia
23. Ocean-continent
24. Continental curst is too buoyant to subduct. Plate breaks off and subduction stops, causing a global change in plate motions.
25. Continent-continent
26. fast spreading of ocean basin means larger ridge volume, increases the sea level and causing flooding of continents.
27. Forms volcanic island arc above the subducting plate (sea/oceans, underwater volcanoes)
28. Formation of subduction zones/trenches
29. Oceanic-oceanic
30. Faults, fracture zones, earthquakes
31. San Andreas Fault
32. Geologic feature/formion
33. Mid-Atlantic Ridge
34. Mid-Ocean Ridge Rift Valley Earthquakes Volcanism
35. Geologic features/formation
36. ⬆️⬇️
37. when plate boundaries slide past each other.
38. ➡️⬅️
38.1. When the plate move toward each other
39. ⬅️➡️
40. When two plate move away to each other.
41. Magma is heated, becomes less dense and rises—then cools, becomes denser and falls.
42. Three types of plate boundaries
43. The lithosphere (crust and upper mantle) is broken into numerous pieces called plates.
44. Theories
45. The age of seafloor increases regularly with distance from the ridge axis.
46. first observed by Brunhes (1906) on land, the north magnetic pole becomes South magnetic pole and South becomes North
47. wegener took the ice-covered areas of the southpole and matched each other .and said they were only partially separated
48. topography is elevated and the structure of axial valley formed by normal faulting suggests tension and extension.
49. There were similar animal and plant species in both continent the mesosaorus is found in the antlantic in south america and africa. They cannot cross the ocean.To .say this continent is just split.
50. Evidences
51. the seafloor occurs in the divergent boundary .while moving away it has heat coming from the mantle .between the two divergent the seafloor is formed
52. Arthur Holmes
53. When we fit Europe and North America together, we find that Appalachians and Caledonides could form a single chain mountain.
54. continents are fit together like jigsaw puzzle pieces
55. Evidences
56. 250 million years ago continents were combined into one supercontinent called Pangaea.
57. Seafloor SpreadingTheory
58. Continental Drift Theory
59. Plate Tectonics Theory
60. Plate Boundaries
61. Dynamic Earth
61.1. Three theories
