Igneous rocks, eg bassalt, were the first to form when the molten lava cooled, then the erosion began.
(the first; to form; T:when the molten lava cooled) (the molten lava; cooled; ) (the erosion; began; T:then) Context(the erosion began,List([84, 101))):(Igneous rocks; were; the first to form)
the erosion began,List([84, 101))
the first the molten lava the erosion Igneous rocks
to form cooled began were
T:when the molten lava cooled
T:then
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