With millions of years of rock piled on top of these swamps, the heat and pressure caused the vegetation to turn into the black carbonaceous substance known as coal.
(millions of years of rock; piled; L:on top of these swamps) (the black carbonaceous substance; known; as coal) (the heat and pressure; caused; the vegetation to turn into the black carbonaceous substance) Context(the heat and pressure caused,List([61, 89))):(the vegetation; to turn; into the black carbonaceous substance)
the heat and pressure caused,List([61, 89))
millions of years of rock the black carbonaceous substance the heat and pressure the vegetation
piled known caused to turn
L:on top of these swamps
as coal
the vegetation to turn into the black carbonaceous substance
into the black carbonaceous substance