Tectonics 2

Tectonics 2

Constructive margins
1. lithosphere spreads apart
  1. magma escapes + makes new crust material
2. e.g Mid Atlantic Ridge
  1. Iceland; Surtsey, Heimey formed along it
  2. 1,000km wide with central rift valley
3. shallow focus earthquakes and volcanic activity
Destructive margins
1. oceanic continental
  1. e.g The Andes
  2. denser oceanic is subducted beneath lighter continental
    1. creates ocean trenches, batholiths, volcanic mountain chains
    2. shallow-intermediate focus earthquakes
      1. e.g Chile 2010
        Subduction of Nazca under South American
2. oceanic oceanic
  1. two oceanic plates converge
    1. makes volcanic island arcs + ocean trenches + earthquakes
      1. e.g Ryukyu Islands
        The Phillipines plate and the Eurasian
        Volcanic activity led to formation
    2. subduction leads to melting (Benioff Zone)
3. continental continental
  1. continental crust doesn't subduct
    1. creates fold mountains (oregeny)
      1. not much earthquake and no volcanic activity
      2. intense folding, faulting + uplifting
  2. e.g Himalayas
    1. Indo-Australian Plate and Eurasian
      1. Mount Everest
Conservative margins
1. Plates slide laterally against eachother
  1. friction creates shallow focus earthquakes, no volcanic activity
2. e.g San Andreas Fault
  1. Pacific Plate (faster) than North American

Resource summary

	Created by Dana Davies over 7 years ago