Where two plates meet and pass past each other. There
are NO VOLCANOES as there is no subduction or volcanic
activity
Movement of the plates is erratic
therefore pressure builds and
causes sudden movement which
results in earthquakes
Case Study:
San Andreas
Fault Line
Destructive Subduction Plate Boundary
Rhyolitic, acidic lava, high in
silica, potentially explosive
eruptions with pyroclastic
flow, lava bombs, ash and
dust, infrequent eruptions,
can go through long dormant
periods, creates large stratovolcanoes
Where two plates move towards each
other, the oceanic plate subducts beneath
the continental plate as it is denser, it melts
as it comes into contact with the
asthenosphere, this then rises and causes a
volcano on the surface on the continental
plates. This also occurs with two oceanic
plates where the faster plate subducts.
Case Study:
Pacific Ring of
Fire
Conservative Plate Boundary
Basaltic, low viscious lava, low in sillica,
frequent eruptions, can be
continuous, form shield
volcanoes, NOT violent
eruptions gases easily escape
Two plates move apart
from each other and
magma rises adding
new land to the plates
Case Study:
Mid- Atlantic
Ridge (Oceanic Ridge)
Case Study:
Eastern African
Rift Valley (Rift
Valley)
Destructive Collision Plate Boundary
Two continental plates collide but there is no
subduction therefore there are no volcanoes. Instead
the sediment on the crust is forced upwards and
folds into huge mountain ranges, this movement
causes earthquakes