The Earth's surface is separated into tectonic plates
There are three types of
plates margins
Destructive margins : are where two plates are moving
towards each other, e.g along the east coast of japan. Where
an oceanic plate meets a continental plate, the denser oceanic
plate is forced down into the mantle and destroyed. This often
creates Volcanoes and ocean trenches. Where two continental
plates meet, the plates smash together, but no crust is
destroyed
Constructive margins are where two plates are moving away from each
other, e.g at the mid-atlantic ridge. Magma rises from the mantle to fill the gap
and cools, creating new crust
Conservative margins are where two plates are moving sideways past each other, or
are moving in the same directionbut at different speeds, e.g along the west coast of
the USA. Crust isnt created of destroyed.