Once the magma cools to form igneous rock, it is gradually worn away by the weather and the fragments are washed down into the sea.
(the magma cools; to form; igneous rock) (it; is gradually worn away; by the weather; T:Once the magma cools to form igneous rock) (the fragments; are washed; down; into the sea)
the magma cools it the fragments
to form is gradually worn away are washed
igneous rock
by the weather T:Once the magma cools to form igneous rock
down into the sea