plate margines and landforms

HideShow resource information
View mindmap
  • plate margins
    • destructive
      • continental plate meets continental
        • eg the indo austrailian plate and the euraisian plate colliding
          • forms young fold mountains
            • the collision buckles the two continental edges
              • this crumples deep roote rocks and sedimentary rocks on the surface
                • e.g. himilayers which due to the continued pressure are still growing in height made from folded sediments.
      • oceanic meets oceanic
        • e.g. pacific plate being sub ducted under the Philippine plate
        • creates island archs
          • pacific plate subducted beneathe phillipeane
            • it partially melts
              • magma rises through the gaps in the phillpiene plate forms submarine volcainoes
                • builds up a cresent shape of volcainoes
                  • continued volcanic activity builds up sea mounts into islands forming an island arch
      • oceianic meets continental
        • landforms
          • deep sea trenches
            • long narrow v shaped sea depressions running along the plate margine eg the chilie peru trench at 8000 km deep and 6000 km long
            • rock travels laterally due to tectonics
              • oceianinc plate cools becoming more dense and sinks once colliding with the continental creating a deep sea trench
          • young fold mountains
            • as the two plates oceanic and continental push together t edge of the continental buckles and gets compressed
              • shortened laterally increased vetically
              • the mountains created considered young as they usually have formed less than 25 million years ago
              • the mountains are made up of a mix of igneous continental crust and sedimentary rocks from river deposits and sediment scraped from the oceanic plate as it is subducted
            • volcanic activity also expands the mountain range from magma created from the sub ducted oceanic plate
    • constructive
      • oceianic
        • sea floor spreading
          • convectin currnts causes the rock to travel laterally abouve
            • the rock below the lithosphere moves a few cm per year dragging the lithosphere abouve with it
              • tensions and high temperatures weaken the plate above until it splits causing a gap to form which is quickly in filled with magmas asthenosphere melts due to a fall in pressure
                • forms an ocean ridge as submarine volcanic activity as the less dense basaltic lava forms a ridge along the plate margin
                  • ocean ridges- eg mid atlantic ridge can rise up to 3000m in hight and formislands such as the Azores
      • continental
        • rift valleys
          • the rock travels laterally due to the convection currents
            • the high temperatures weaken the plate causing the plate to bulge creating horsts
              • between the horsts the crust collapses creating a valley called a graben
                • eg the eathiopean highlands and the east africain rift as the somailian plate is splitting from the africain continent
    • conservative
      • hazards
          • Plates lock and stress builds up forms shallow focus earthquakes
      • 2 plates sliding alongside each other
        • e.g. st Andres fault California and Haiti
        • no subduction or magma created no volcanic activitey
        • no landforms created


No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Plate tectonics resources »