Alfred Wegener ( VAYG-uh- nur )

1. Alfred Wegener(VAYG-uh-nur) • Continental drift • Claimed that all the continents once were together forming one large continent called Pangaea. • Alfred Wegener German scientist (weather man) came up with the idea

2. Continental drift-Fact or fiction? Support/ Evidence Opposition/ problems What Continental drift couldn’t answer! How can the continents move? No mechanism to make them move Ocean crust is to hard for the continents to move through • Continents seem to fit together • Fossil record seems to match • Rock structures match • Rock ages match • Changes in climates • Glacier debris

3. Continental DriftPossible mechanism?

4. Clicker question • The term given by Alfred Wegener, which means “ all land”. • Eurasia • Panthalassa • Pangaea • Continentolossal

5. Modern EvidencePlate Tectonic theory Mid-Ocean ridges & Sea floor spreading • Mid-Ocean ridge • Large under water mountain range, with a deep valley down the center • Ocean floor was moving, • Why not continents? • Sea floor spreading • new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge

6. Modern EvidencePlate Tectonic theory Paleomagnetism • Study of Earth’s magnetic field through rocks and minerals • Shown by different magnetic properties preserved in the rock record • Magnetic poles reverse • NS, SN • Convection • Hot magma rises cool magma sinks • Causes movement within the mantle

7. What scientists discovered that there is a cycle in which the continents move. • Supercontinent cycle: continents come together and break apart • Wegener’s Pangaea

8. Breaking up “it’s not you it’s me” • During the mesozoic era Pangaea began to split up. Sniff sniff so sad  • When it did it formed two separate continents named Laurasia and Gondwanaland.

14. Clicker question • 13, 227,735, 700, 000, 000, 000, 000, 000 lbs.(13 octillion, 227septillion,735 sextillion 700 quintillion pounds) How much does the Earth weigh (mass) in pounds?

15. The Crust (Lithosphere) • Oceanic: more dense and younger • 510 km thick • Continental: Older less dense material made from recycling of Oceanic crust • 1580km thick

16. Earth’s layers • Mantle: Thickest layer; made of two parts • Lower mantle • Solid • Upper mantle/ Asthenosphere • “Putty like” and flows even though it is solid rock (very hot and under a lot of pressure) • Moho- • (Mohorovic discontinuity) • Boundary that separates the mantle from the crust. • Earth quakes waves speed up.

17. Earth’s layers • Lithosphere- • Crust: • Oceanic • Continental • Thinnest layer (5-70km) • Even thinner when underneath the ocean. • The wrapper • Crust • Moho -Waxy part of wrapper • Mantle- Shell • Upper and lower • Core- tootsie roll • Outer liquid • Inner solid

18. How do we know? Seismic waves caused by earth quakes Waves travel at different speeds through different mediums. (a medium is the material a wave travels through) Primary (P) waves: Travels fast through liquid, solid, gas Secondary (S) waves: Solids only and slower

19. Earth’s layers • Moho- • (Mohorovic discontinuity) • Boundary that separates the mantle from the crust. • Earth quakes waves speed up. • Moho must be more dense

20. Plate Movement

21. Types of plate boundaries • Divergent • Pulling apart • Ex. • Mid-Atlantic ridge • Great rift Valley Africa

22. Types of plate boundaries • Transform Boundary • One plate slides past another • Ex. San Andreas fault • Causes earthquakes in California

23. When will California fall off of the United States? NEVER !!!

24. Types of plate boundaries • Convergent • Two plates crashing into each other • Three types of plate collisions • Continent-Continent • Indo-Australian and Eurasian plates • Himalayan mountains. Formed by this grow an inch a year

25. Types of plate boundaries • Ocean to Continental • Ocean plate is more dense subducts under continental plate. • Ex. • Alaska island arc

26. Types of plate boundaries • Ocean-Ocean • Two oceanic plates collide • Ex. • Marianas trench • 1,600 miles long,43 miles wide, 36,200ft deep • Island arcs (volcanoes)

27. Clicker question What will most likely form at a oceanic and continental plate convergence? Non-geologically active volcanoes Craters Hot spots Composite volcanoes

28. Tectonic plates Major: Pacific North American South American Eurasian African Indo-Australian Antarctican Minor:Juan de Fuca Coco's plate Nazca Caribbean

29. Plate tectonics theory • There are 52 tectonic plates. • 14 major plates • 38 minor plates So what is going on at all these plates? The theory that the earth’s lithosphere is divided into plates that move on the Asthenosphere. ASK THIS How many plates are there Mr. Hernandez?

31. IGNEOUS ROCKS • Igneous rocks are formed from molten material • (magma). A. Extrusive igneous rocks are formed when molten rock cools above ground. Usually they are formed after the material has been erupted by a volcano. This molten material cools quickly. No crystals are visible to the eye.

32. Intrusive igneous rocks are formed when molten rock cools below ground. These rocks cool very slowly. There is lots of time for visible crystals to grow

33. Clicker question • The parent material for all rocks is: • Quartz • Magma • Silica • Granite

34. Granite  Igneous rock textures Coarse mineral grains easily visible (grains several mm in size or larger)

35. Igneous rock textures Fine mineral grains smaller than 1mm (need hand lens or microscope to see minerals)

36. Igneous rock textures Vesicular (Open spaces, bubbles)

37. Igneous rock textures Glassy Shiny no visible crystals (looks like glass)

38. Felsic VS Mafic Felsic: rich in light minerals feldspar and quartz Mafic: Rich in dark minerals Magnesium and Iron (Ferric)

39. Clicker question • The size and arrangement of crystalline grains in igneous rock is called • Luster • Hardness • Density • Texture

40. Intrusive rock features Batholith: Largest intrusions of rock “deep rock” Laccolith: Intrusion of rock that is parallel to the rock layers “lake of rock” Dikes: Vertical cross cutting layer of rock Sills: Parallel sheet of rock

41. Volcanoes

42. Hawaii TYPES OF VOLCANOES SHIELD VOLCANOES Mostly made up of lava flows Highly Mafic Ex. Hawaiian islands

43. Shield Volcanoes Shape: Very large but gentle slopes Composition: Low silica Low gases Eruptive Style: ?

44. Types of Volcanoes • Cinder cone Volcano • Mostly made of cinders and other fragments • Ex. Paricutin in Mexico

45. Paricutin volcano in Angahuan, Mexico was born on March 4th 1943. How do we know this? Dionisio Pulido, was plowing his field when he noticed steam coming up from the footprints of the oxen, pulling his plow. Soon, the earth shook and cracks began to form in his field. Dionisio panicked and tried to fill the steaming holes, while his wife called all the villagers to help. As you might have guessed, the volcano was born in spite of their efforts. Luckily, no one was killed. However, the village was eventually covered by lava, sparing only the front and back walls of the cathedral.

46. Cinder Cone Volcanoes Shape: Very small but steep slopes Composition: Medium silica High gases Eruptive Style: ?

47. Types of Volcanoes • Composite Volcanoes (stratovolcano) • Alternating layers of ash and Lava flows • Steep sides • Ex. Mt. St Helens • Cascade mountain range • Mt. Rainier • Mt. Pinatubo • Mt. Fuji

48. May 17,1980

49. MAY 18, 1980

50. TODAY