1. Geology of the Northwest

2. James Hutton “The Father of Geology” Uniformitarianism

3. Scientific Method Raise question Gather data

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

5. 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

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

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

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

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

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

13. The Major Plates

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

15. What Drives Plate Tectonics? Internal Heat

16. 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)

17. Divergent Boundary Results in the formation of Oceanic Crust

18. Examples:

19. Transform Boundary

20. Transform Example

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

22. Example: Pacific Northwest

23. Example: Andes Mountains

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

25. 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)

27. Volcanoes

28. Earthquake Distribution

29. Topography

30. Rock Age

31. 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