A bed of ancient lava seemed to mark the commencement of the <e1>eruption</e1> from the <e2>craters</e2> of the great chain of the Andes.
A bed of ancient
A bed of ancient lava seemed to mark the commencement of the eruption from the craters of the great chain of the Andes.
<triplet> eruption <subject> craters <object> Entity-Origin(e1,e2)