1. Geology of the Northwest

2. NW Stories in Stone Glacier National Park, MT North Cascades NP

3. NW Stories in Stone John Day Fossil Beds National Monument Gingko Petrified Forest State Park

4. NW Stories in Stone Columbia Plateau Mt. St. Helens

5. NW Stories in Stone Dry Falls State Park Puget Sound

6. NW Stories in Stone 1700 Quake Portland Volcanoes

7. James Hutton “The Father of Geology” Uniformitarianism “The Present in the Key to the Past.”

8. Geology of the Northwest

9. Scientific Method Raise question Gather data

10. Scientific Method Raise question Gather data Form hypothesis Test and modify hypothesis Scientific Theory Scientific Law

11. 1.Earth’s “surface” is broken into rigid plates 2.Plates move 3.“Geology happens” where the plates interact with one another Basic Plate Tectonics

12. What do we mean by the Outer Part of the Earth?

13. Three Layers: Based on Composition LayerComposition CrustRock: Felsic & Mafic MantleRock: Ultramafic CoreMetal: Iron & Nickel

14. Crustal Properties CrustDensityCompositionThicknessAge Continental ~2.8 g/cm 3 Felsic (High in Silica) Thick: 20-70 km Old: up to 4 Byrs Oceanic ~3.2 g/cm 3 Mafic (Low in Silica) Thin: 2-10 km Young: <200 Mys

15. Five Layers: Based on Physical Properties Layer“State” LithosphereSolid / Rigid AsthenospherePartly Liquid / “Plastic” Lower MantleSolid Outer CoreLiquid Inner CoreSolid

17. Part #1 of Plate Tectonics Definition Earth’s “surface” is broken into rigid plates Surface = Lithosphere (includes Continental Lithosphere and Oceanic Lithosphere)

19. The Major Plates

20. Part #2 of Plate Tectonics Definition Plates move… …on the “plastic” Asthenosphere

21. What Drives Plate Tectonics? Internal Heat

22. How do we Know How Fast Plates Move? One Method: Mantle Hot Spots

23. Volcano Forms Above Hot Spot Hot Spot

24. Plate Moves 10 7 40 Hot Spot Age in Million Years (Myr)

25. Plate Velocity Plate Velocity = Distance Traveled / Age of Volcano 10 7 40 Age in Million Years (Myr) Distance Moved = 1000 km Hot Spot

26. Hawaiian Islands

27. Part #3 of Plate Tectonics Definition “Geology happens” where the plates interact with one another How do they interact? 1.Pull Apart from one another (Diverge) (New rock is formed) 2.Push into one another (Converge) (Rock is destroyed) 3.Slide past one another (Rock is conserved)

28. Divergent Boundary Results in the formation of Oceanic Crust

29. Examples:

30. Transform Boundary

31. Transform Example

32. San Andreas Fault

33. Convergent Boundary: Subduction Results in the formation & growth of Continental Crust and destruction of Oceanic Crust Melting Produces More Felsic Magma

34. Example: Pacific Northwest

35. Example: Andes Mountains

36. Convergent Boundary: Collision Results in the growth of Continental Crust

37. Note Alternative Names: 1. Divergent (also called Spreading Ridges, Rifts, and Mid-Ocean Ridges) 2. Transform (also labeled as Strike-Slip Faults) 3. Convergent: Oceanic-Continental (also labeled as Subduction Zones) 4. Convergent: Continental-Continental (also labeled as Collision Zones and Thrust Faults)

39. Volcanoes

40. Earthquake Distribution

41. Topography

42. Rock Age

43. 1.Earth’s lithosphere is broken into 12-24 rigid plates 2.Plates move about 1-10 cm/yr on the plastic Asthenosphere 3.“Geology happens” where the plates interact with one another along Divergent, Transform, Subduction and Collisional Boundaries Basic Plate Tectonics - Revised