Download Plate Margin

Tectonic Activity and Plate Margins– in the right hand column add EXTRA case studies in the empty spaces (with thanks to D McGuinness)
Plate Margin
NAME
Constructive
(Spreading or Divergent
margins)
Movement of Plates
Divergent: two plates moving away
from each other.
Tectonic Features
New crust is formed from upwelling
magma:
 mid-oceanic ridges;
shield volcanoes;
 shallow focus
earthquakes;
 rift valleys.
Examples
1 Mid Atlantic ridge.
Divergent spread of Iceland.
2……………………………………………………………
3…………………………………………………………..
Continental rift valleys
Destructive
(Convergent)
(1) Subduction
Convergent: two plates moving
towards each other.
1a) Oceanic to oceanic: trenches,
island arcs, explosive volcanoes,
earthquakes.
1b) Oceanic to continental:
trenches, fold mountains, explosive
volcanoes, earthquakes.
(2) Collision
Conservative /Transform Passive: Two plates shearing past
each other.
Not at a plate boundary.
Hot Spots: may be near the centre
of a plate.
2) Continental to continental: fold
mountains, shallow focus
earthquakes.
 Shallow focus
earthquakes.
Plume volcanoes
1 Andean type: Nazca plate subducting under South American
plate.
2
Himalayan type: Indian plate colliding with Eurasian plate.
3
………………………………………………………………
1
2
San Andreas fault: Pacific plate and North American
plate.
…………………………………………………………….
1
2
3
Hawaiian islands: Emperor seamount chain.
Yellowstone supervolcano.
………………………………………………………….