DO NOW Pick up notes sheet.

REVIEW #9

REVIEW #9

REVIEW MAFIC minerals are: More dense Associated with Oceanic crust FELSIC minerals are: Less dense Associated with Continental crust Where would you most likely find MAFIC minerals? Where would you most likely find FELSIC minerals?

Plate Tectonics and Earth’s Changing Surface

CONTINENTAL DRIFT Continents move: caused by sea-floor spreading. widening sea floor. acts as a conveyor belt. drifted to their present locations

CONTINENTAL DRIFT Supercontinent cycle: Single land masses in past. Pangaea – “all Earth” Pangaea split east to west forming Laurasia and Gondwanaland. Suggests supercontinents will form in future.

TECTONIC PLATES – BROKEN CRUST Broken pieces of Lithosphere. Move on top of Asthenosphere. Pulled by convection in mantle. Fit together like puzzle pieces. Various sizes and shapes.

TYPES OF CRUST Lithosphere crust: Ocean Crust - Mafic More Dense Continental Crust - Felsic Less Dense Movement: Together Apart Slide past

CONVERGENT PLATE BOUNDARIES Plates move together. Ocean – Continental Three types. Ocean – Ocean Continental – Continental

CONVERGENT PLATE BOUNDARIES Ocean – Ocean Ocean plates come together deep ocean trench, volcanic arc.

CONVERGENT PLATE BOUNDARIES Ocean – Continental dense ocean crust slips under less dense continental crust. volcanoes, mountains form.

CONVERGENT PLATE BOUNDARIES Continental – Continental Continental plates come together. Folded mountains rise.

CONVERGENCE: SUBDUCTION Latin, means “carried under”. Convergent zones. One plate slips under mantle. Oceanic plates slip into continental ones. Where ocean plates meet, deep ocean trenches form. Partial melting creates volcanoes near trenches.

DIVERGENT PLATE BOUNDARIES Plates move apart. Magma rises to form new land. Builds Oceanic crust.

DIVERGENT PLATE BOUNDARIES Landforms: Ocean Ridges and Rift Valleys

DIVERGENT PLATE BOUNDARIES

DIVERGENCE: SEA FLOOR SPREADING Plates move outward. Age of ocean crust older farther from center Magma meets water - cools and solidifies. Ridge forms around crack or rift at center. Sediment builds up past ridge - deeper farther from center.

PLATE BOUNDARIES: TRANSFORM Plates sliding horizontally past one another. Not smooth – rocks lock and scrape. No magma. Fracture zones created at mid ocean ridges.

PLATE BOUNDARIES: TRANSFORM Example: San Andreas Fault.

FAULTS AND FORCES Breaks in a body of rock along which crust plates move alongside each other in opposite directions. Reverse fault plates PUSH TOGETHER. Destructive Force. Convergent boundaries.

FAULTS AND FORCES Normal fault plates PULL APART Divergent boundaries Constructive Force Strike-slip fault plates SLIDE PAST each other Neutral Force Transform boundaries

STRESSES Forces that deform crust. Types of stresses include: Compression press or squeeze together. plates collide. Convergent boundary. TAFFY PULL!

STRESSES Tension stretch a rock, or pull a plate apart. Divergent boundary Shear lateral motion, causes plates to slide past each other. Transform boundary TAFFY PULL!

PLATES, FAULTS, STRESSES AND LANDFORMS Boundaries Force Stresses Faults Landforms Convergent Destructive Compression Reverse Ocean Trenches and Mountains Transform Neutral Shear Slip-strike Offset Geology Divergent Constructive Tension Normal Rift Valleys and Mid-Ocean Ridges

MATCHING THE DIAGRAMS… Convergent? Reverse Fault? Shear? Transform? Slip-Strike Fault? Tension? Divergent? Normal Fault? Compression? B B C C C A A A B

Mapping Earth’s Drifting Plates TODAY’S ACTIVITY Mapping Earth’s Drifting Plates

TO DO Work on Mapping Earth’s Drifting plates now.