1.8 Plate Boundaries Flashcards
Convergent Plate Boundary (Oceanic + Continental)
Eg Nazca and S America or Pacific + Eurasion. Fold mountains, volcanoes, ocean trenches and earthquakes are formed. The Andes Mountain Range was formed from this
Happen when oceanic crust goes below continetal crust
Convergent Plate Boundary (Continental + Continental)
Eg Eurasion and Indo - Australian. Fold mountains, volcanoes and ocean trenches are formed. The Himilayes were formed from this
When 2 plates push towards each other moving the land upwards
Divergent
Eg African and S American or Eurasion and N American. Shield volcanoes, sea floor spreading and ridges happen. The Mid Atlantic Range was formed from this
When the 2 plates are moving away from each other, releasing magma and as it cools new land is formed
Conservative
Eg Pacific and N American. Volcanoes and faults form. The San Andreas fault in California was formed from this
When 2 plates grind against each other and friction builds up, then they split causing these to happen
Composite Volcano
Convergent plate boundary. Made of lava + ash. High silica content - viscious. Lava flows short distance before cooling. Violent + frequent eruptions. Can have lava bombs + pyroclastic flows
Shield Volcano
Divergent plate boundary. Low with gently sloping sides. Low silica content lave. Flows long distance before cooling. Eruptions are frequent but gentle
Hotspot Volcano
Can happen in middle of plates. Mantle plumes - hot spots. When it reaches asthenosphere it melts lithosphere. Super heated rock, NOT magma. Plates move, creating island chains. Hawaii is a great example