PLATE TECTONICS

http://volcano.und.edu/vwdocs/vwlessons/plate_tectonics/introduction.html

Continental Crust

• Cooling rate• Crystal size• Density • Composition• Thickness

http://www.amonline.net.au/geoscience/images/earth_diagrams/cont_oceanic_crust.gif

Oceanic Crust

• Cooling rate• Crystal size• Density• Composition• Thickness

http://faculty.weber.edu/bdattilo/parks/plume_ocean.jpg

Lithosphere/Asthenosphere

Tectonic Plate

• is a rigid piece of lithosphere floating on a partially plastic substrate (asthenosphere).

Pangea

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

http://www.enchantedlearning.com/subjects/dinosaurs/glossary/Pangaea.shtml

http://www.enchantedlearning.com/subjects/dinosaurs/glossary/Pangaea.shtml

Evidence for Plate Tectonics

• Continents ‘fit’ together

Evidence for Plate Tectonics

• Continents ‘fit’ together• Fossil evidence

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations• Climate distribution

Location of Trenches, Ridges, Mountains

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations• Climate distribution• Location of mountain ridges, rifts,

mid-ocean ridges, trenches

Testing the Sea-Floor Spreading Hypothesis

Magnetization

http://www.ucmp.berkeley.edu/geology/tecmech.html

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations• Climate distribution• Location of mountain ridges, rifts,

mid-ocean ridges, trenches• Magnetic pattern of rock

Same Age Rocks

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations• Climate distribution• Location of mountain ridges, rifts,

mid-ocean ridges, trenches• Magnetic pattern of rock• Common rock formations: same age

Volcano

http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Plate%20Tectonics/Plate%20Tectonics/VolcanoStructure.jpg

Earthquake

• http://news.bbc.co.uk/nol/shared/spl/hi/world/04/earthquake/img/earthquake.gif

Ring of Fire

http://pubs.usgs.gov/gip/dynamic/understanding.html

The Hawaiian - Emperor Volcanic Chain

LOCATION OF HOT SPOTS

Evidence for Plate Tectonics

• Continents fit together• Fossil distribution• Glacier evidence: deposits, striations• Climate distribution• Location of mountain ridges, rifts,

mid-ocean ridges, trenches• Common rock formations: same age• Magnetic pattern of rock• Location of earthquakes and volcanoes

How does it work?

Wegener’s Continental Drift

Wegener’s Theory Problems

1) Continents plowing through the crust would destroy the crust

2) Continents are not moving apart at the speed Wegener proposed

• Didn’t have a good explanation of the mechanism involved

Holme’s Convection Currents

Convection currents

• Gravity causes the heated mantle to sink

• The mantle heats up near the core and then rises again

• Conduction is the transfer of heat between 2 materials in direct contact with each other

library.thinkquest.org/C003124/images/convect.jpg

http://www.wisc-online.com/objects/index_tj.asp?objID=SCE304Click animation

• Movement of mantle by convection allows melting and force to move plates

CONVECTION

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

Hot Spots – Hawaiian Islands

http://geology.com/nsta/plate-tectonics-cover.gif

Evidence for Convection

Sea-Floor Spreading Hypothesis by Hess & Deitz

CLICK Animation: http://www.uwsp.edu/geo/faculty/ritter/glossary/s_u/sea_flr_spread.html

SEA FLOOR SPREADING

SUBDUCTION

Types of Plate Boundaries

Plate BoundaryTransform, Divergent & Convergent

http://www.ifa.hawaii.edu/~barnes/ast110_06/tprai/Tectonic_plate_boundaries.png

SIMULATIONS ON ALL BOUNDARY TYPESCLICK http://www.pbs.org/wgbh/aso/tryit/tectonics/shockwave.html

CONVERGENT BOUNDARIES

Types of Plate Boundaries

• Convergent boundaries

Convergent BoundaryOceanic & Continental

CLICK http://geology.com/nsta/convergent-boundary-oceanic-continental.gif

Andes MountainsConvergent Oceanic & Continental

blue.utb.edu/paullgj/images/Conv_Cont_Ocean.JPG

CLICK http://www.pbs.org/wgbh/aso/tryit/tectonics/convergent.html

Convergent BoundaryOceanic & Oceanic

http://geology.com/nsta/convergent-boundary-oceanic-oceanic.gif

Japan or Aleutian IslandsConvergent Oceanic & Oceanic

ceeps.colostate-pueblo.edu/.../smM1P1Fig15.gif

Convergent BoundaryContinental & Continental

http://geology.com/nsta/convergent-boundary.gif

HimalayasConvergent Continental & Continental

CLICK Convergent Simulation

http://www.pbs.org/wgbh/aso/tryit/tectonics/crush.html

DIVERGENT PLATES

Types of Plate Boundaries

• Convergent Boundaries• Divergent Boundaries

Divergent BoundaryOceanic

• Sea-floor spreading, Mid-Ocean Ridges

CLICK http://geology.com/nsta/divergent-boundary-oceanic.gif

Mid Atlantic RidgeDivergent Oceanic

• http://www.odp.usyd.edu.au/odp_CD/sr/images/textpics/Fig7.gif

DIVERGENT SIMULATIONSCLICK http://geology.com/plate-tectonics.shtmlCLICK http://www.pbs.org/wgbh/aso/tryit/tectonics/divergent.html

Divergent BoundaryContinental

• Rift Valley

http://geology.com/nsta/divergent-boundary-continental.gif

Mid Atlantic RidgeDivergent Oceanic

• http://www.odp.usyd.edu.au/odp_CD/sr/images/textpics/Fig7.gif

DIVERGENT SIMULATIONSCLICK http://geology.com/plate-tectonics.shtmlCLICK http://www.pbs.org/wgbh/aso/tryit/tectonics/divergent.html

TRANSFORM BOUNDARIES

Types of Plate Boundaries

• Convergent boundaries

Transform Boundary

TRANSFORM SIMUALTIONSCLICK http://geology.com/nsta/transform-boundary.gifCLICK http://www.pbs.org/wgbh/aso/tryit/tectonics/transform.htm

San Andreas FaultTransform Boundary

www.wiley.com/college/herenow/ptect/pt-map1.gif

Types of Plate Boundaries

• Convergent Boundaries• Divergent Boundaries• Transform Boundaries

http://geology.csupomona.edu/drjessey/class/Gsc101/Plate.html

Location of Plate Boundaries

Seven Major Plates

• Pacific • North American • South American • African • Eurasian • Antarctic • Indo-Australian

External Energy For Earth

• Sun & Moon keeps air and sea in motion, shapes surface

• Sun warms atmosphere & crust unevenly creating winds

• Winds drive ocean currents and water cycle• Erosion from winds, rains, rivers, glaciers, and

waves shape surface• Weathering from winds and rains• Sun & Moon Gravitational Energy, produces

tides• Planetesimal collisions

Internal Energy for Earth

• Radioactive element decay• Core heat from layers pressure• Convection currents• Volcanoes• Hot Springs• Earthquakes