Earth Science

1. Earth Science The following slides are an overview of the Earth, how the plates of the Earth move, and the features created. Pay close attention to the pictures.

2. The Earth and the Layers • Crust– outside layer; two layers – continental crust and oceanic crust; thinnest • Mantle– solid but acts like a liquid; has plasticity • Outer core – liquid • Inner core - solid

4. CONVECTION CURRENTS • Responsible for plate movement • Method of heat transfer • Circular motion like a conveyor belt at the grocery store • Follow arrows for direction of motion

5. CONVECTION CURRENTS

6. PLATES • Crust is broken up into different plates • Some are oceanic and some are continental • Some plates are colliding • Some plates are sliding past each other • Some plates are spreading apart

9. Features Formed at Boundaries • Convergent – colliding or coming together • Divergent – two plates separating or moving apart (diving away) • Ocean floor spreading – two plates are spreading apart and new ocean floor is created • Subduction zone – one plate is going down under the other

11. Mid-ocean Ridge

12. Hawaiian Islands Plate is moving and new islands are being created

13. Mountain Building • Mountains are built from colliding plates • Can be continental – continental collision • Can be oceanic – continental collision often forming volcanic mountains

18. STRATIGRAPHY

19. PRINCIPLE OF ORIGINAL HORIZONTALITY • The sediments are deposited in water form as horizontal or nearly horizontal layers. • If a layer of sediment is tilted, then a force acted upon it AFTER it was deposited. These layers were deposited AFTER the other layers were tilted. These layers were deposited horizontally.

20. LAW OF SUPERPOSITION • In undisturbed sedimentary rocks, the younger layers are on the top and older rock layers are on the bottom YOUNGEST OLDEST

21. Youngest Oldest A force acted upon the layers causing folding.

22. PRINCIPLE OF CROSS-CUTTING • The disturbance (intrusion or fault) is younger than the rock layers that it crosses. YOUNGER THAN LAYERS IT CROSSES OLDEST LAYER

23. Which layer is the oldest? Y X N P This had to be here first before P formed. W

24. Correctly sequence the order of the layers and intrusions from OLDEST to YOUNGEST. SGEPTXC M C, X, T, P, E, G, S, M

25. Did the fault happen before or after the last layer of deposition? Youngest Oldest

26. Which layer is the oldest? What is the last thing to happen? OLDEST = C F Z R M C LAST THING = F G

27. GT R W Q Did this fault happen before or after the dike? D X Dike Sequence?

28. Sequence the layers, be sure to include the tilting and erosion in your sequence. Limestone Mudstone Shale, sandstone, mudstone, limestone, tilting, erosion

29. Sequence the layers OLDEST to YOUNGEST, be sure to include the folding and the fault. M R X C - fault B A A, B, X, R, M, Folding, fault

30. Which statements are TRUE? • The top sandstone is the oldest. • The bottom shale is older than the bricks. • The fault is older than the intrusion. • The intrusion is younger than the brick. • The house is built on the oldest layer. False - youngest True False - younger True False - youngest