Plate Tectonics & Major Geological Events

1. Plate Tectonics & Major Geological Events

2. Plate Tectonics (Review) • The Earth’s crust and upper mantle are broken into sections called plates. • The plates of the lithosphere float on the asthenosphere. • Two Types of Plates: • Ocean plates - plates below the oceans • Continental plates - plates below the continents

3. Major Plates Boundaries & Their Relative Motions

4. I CAN… • describe various landforms created by different plate movements.

5. Plate Boundaries divide • Divergent Boundary –_____ • Convergent Boundary – ________ • Transform Fault Boundary –________________________ collide slide

6. Divergent Boundaries • Boundary between two plates that are moving apart or rifting   • RIFTING causesSEAFLOOR SPREADING

7. Features of Divergent Boundaries • Mid-Ocean Ridges (Two Oceanic Plates) • Rift Valleys (Two Continental Plates) • Ocean Basins • Fissure Volcanoes

8. Mid-Ocean Ridges & Rift Valley

9. Divergent boundary of two continental plates. Creates a __________. Example: _____________ rift valley East African Rift

10. Deep-ocean basin Continental margin Continental margin Submarine canyon profile (cut through continental shelf) Sediment Continental shelf Continental slope Oceanic ridge Sediment Continental rise Continental crust (granitic) Continental crust (granitic) Oceanic crust (basaltic) Oceanic crust (basaltic) Asthenosphere Ocean Basins are generated at divergent plate boundaries, but also disappear down seduction zones in convergent plate boundaries.

11. Convergent Boundaries • Boundaries between two plates that are colliding   • There are 3 types…

12. Type 1: Ocean plate & Continental Plate • Ocean plate colliding with a less dense continental plate • SUBDUCTION ZONE: where the less dense plate slides under the more dense plate • VOLCANOES occur at subduction zones

13. Convergent boundary of an oceanic plate and a continental plate. Forms a _______ mountain range and a ______. Examples: _______ or _______ Mts volcanic trench Andes Cascades

14. Trenches are arc-shaped depressions in the ocean floor caused by the subduction of a converging ocean plate. Most trenches are around the edges of the active Pacific. The ocean’s greatest depth is the Mariana Trench where the depth reaches 36,163 miles below sea level.

15. Type 2: Ocean Plate & Ocean Plate • Ocean plate colliding with another ocean plate • The less dense plate slides under the more dense plate creating a SUBDUCTION ZONEcalled a TRENCH

16. Convergent boundary of two oceanic plates. Creates an ________ and a _____. Example: _____ island arc trench Japan

17. Type 3: Continental Plate & Continental Plate • A continental plate colliding with another continental plate • Have Collision Zones: a place where folded and thrust faulted mountains form.

18. Convergent boundary of two continental plates. Forms a ______ mountain range. Examples: ___________, Alps, ______________ Himalayas folded Appalachians

19. Transform Fault Boundaries • Boundary between two plates that are sliding past each other • EARTHQUAKES along faults

20. Transform-fault boundary where the North American and Pacific plates are moving ____ each other. Example: ________________ in California past San Andreas Fault

21. Plate Boundaries Review • Places where plates move apart are called _____________ boundaries. • When continental plates diverge a ___________ is formed. • When two oceanic plates converge what is created? _________________ • The Appalachians formed mainly from continental plate collisions and therefore are a __________ mountain range. • The force moving the plates is ____________ . divergent rift valley an island arc and a trench folded Convection currents