Processes of Lithosphere

1. Processes of Lithosphere

2. Lithosphere • Rigid outermost shell of a rocky planet • On earth, comprises the crust and the upper mantle

4. The Rock Cycle Thinking about relationships among the major rock groups

5. Major Rock Groups • Igneous • Formed from a melt (molten rock) • Plutonic (intrusive):slow cooling and crystallization • Volcanic (extrusion): quick cooling at the surface • Sedimentary • Formed at the Earth’s surface • Metamorphic • Changed by pressure, temperature and fluids.

6. Fig. 2.9 MAGMA

7. IGNEOUS Crystallization MAGMA

8. IGNEOUS Plutonic Crystallization MAGMA

9. Volcanic IGNEOUS Plutonic Crystallization MAGMA

10. Weathering Volcanic IGNEOUS Plutonic Crystallization Uplift MAGMA

11. Weathering • Chemical – changing composition (acid rain) • Physical – Breaking apart rocks, moving soils, etc • Soil is result of weathering of rocks and includes weathered particles

12. SEDIMENT SEDIMENT Weathering Volcanic IGNEOUS Plutonic Crystallization Uplift MAGMA

13. Erosion SEDIMENT Weathering Transport Deposition Volcanic IGNEOUS Plutonic SEDIMENTARY Crystallization Uplift MAGMA

14. Erosion SEDIMENT Weathering Transport Deposition Volcanic IGNEOUS Plutonic SEDIMENTARY Crystallization Uplift MAGMA

15. Erosion SEDIMENT Weathering Transport Deposition Volcanic IGNEOUS Plutonic SEDIMENTARY Increased P&T METAMORPHIC Crystallization Burial Uplift MAGMA

16. Erosion SEDIMENT Weathering Transport Deposition Volcanic IGNEOUS Plutonic Can you see any shortcuts? SEDIMENTARY Increased P&T METAMORPHIC Crystallization Melting Burial Uplift MAGMA

17. Erosion SEDIMENT Weathering Transport Deposition Volcanic IGNEOUS Plutonic SEDIMENTARY Increased P&T METAMORPHIC Crystallization Melting Burial Uplift MAGMA

18. In Conclusion… • The rock cycle demonstrates the relationships among the three major rock groups • It is powered by the interior heat of the Earth • The energy from the sun • It involves processes on the Earth’s surface as well as the Earth’s interior.

19. The Structure of the Earth and Plate Tectonics

20. Structure of the Earth • The Earth is made up of 3 main layers: • Core • Mantle • Crust Mantle Outer core Inner core Crust

21. The Crust • This is where we live! • The Earth’s crust is made of: Continental Crust- buoyant (less dense than oceanic crust) Oceanic Crust- dense (sinks under continental crust)

22. What is Plate Tectonics?

23. If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

24. Plate Tectonics • The Earth’s crust is divided into 12 major plates which are moved in various directions. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

25. World Plates

26. What are tectonic plates made of? • Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle.

27. Plate Movement • “Plates” of lithosphere are moved around by the underlying hot mantle convection cells

28. Divergent Convergent Transform Three types of plate boundary

29. Spreading ridges As plates move apart new material is erupted to fill the gap Divergent Boundaries

30. Iceland: An example of continental rifting • Iceland has a divergent plate boundary running through its middle

31. Convergent Boundaries • There are three styles of convergent plate boundaries • Continent-continent collision • Continent-oceanic crust collision • Ocean-ocean collision

32. Continent-Continent Collision • Forms mountains,e.g. European Alps, Himalayas

33. Himalayas

34. Continent-Oceanic Crust Collision • Called SUBDUCTION • Area is called the subduction zone

35. Transform Boundaries • Where plates slide past each other Above: View of the San Andreas transform fault

37. Volcanoes and Plate Tectonics… …what’s the connection?

38. Pacific Ring of Fire Volcanism is mostly focused at plate margins

39. - Subduction - Rifting - Hotspots Volcanoes are formed by:

40. Subduction • Form new melt that will rise through the crust to be erupted at the surface

41. Rifting • Form new melt that will rise through the crust to be erupted at the surface

42. Hot Spots • Does not occur along a plate boundary. • Form in the middle of tectonic plates

43. Volcanic Eruptions • Pyroclastic Flow – cloud of ash and debris • Travel at hundreds of mph • Hundreds of degrees

44. Volcanic Eruptions • Lahar – mud flows which are very destructive to landscape

45. Volcanic Eruptions http://www.youtube.com/watch?v=UK--hvgP2uY • “Ash” emitted includes small stones • Very dense • Chokes life • Blots out sunlight • Causes wide range temperature drops

46. Earthquakes and Plate Tectonics… …what’s the connection?

47. As with volcanoes, earthquakes are not randomly distributed over the globe • At the boundaries between plates, friction causes them to stick together. When built up energy causes them to break, earthquakes occur. Figure showing the distribution of earthquakes around the globe

48. Where do earthquakes form? Figure showing the tectonic setting of earthquakes

49. Fault Lines • Strike – slip • Reverse • Normal

50. Earthquake Anatomy • Focal point – where the actual earth quake originated underground • Epicenter – location of earth quake on earth’s surface • Above the focal point