premise: The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust.
hypothesis: Gabbro is a dark dense rock that can be found in the oceanic crust.
hypothesis_graph_structure: Gabbro<>is<>a dark dense rock that can be found in the oceanic crust$$$a dark dense rock<>can be found<>in the oceanic crust