( ( Throughout ( ( the history ) ( of ( the earth ) ) ) ) ( , ( ( ( ( continental and ) oceanic ) crust ) ( ( have ( been ( ( ( ( created ( by ( ( magma formation ) ( in ( ( the ( deep ( earth 's ) ) ) mantle ) ) ) ) ) , ) and ) ( ( mixed ( into ( the mantle ) ) ) ( by ( subduction ( at ( the ( ocean trenches ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN Throughout) (NP (NP (DT the) (NN history)) (PP (IN of) (NP (DT the) (NN earth))))) (, ,) (NP (ADJP (JJ continental) (CC and) (JJ oceanic)) (NN crust)) (VP (VBP have) (VP (VBN been) (VP (VP (VBN created) (PP (IN by) (NP (NP (NN magma) (NN formation)) (PP (IN in) (NP (NP (DT the) (JJ deep) (NN earth) (POS 's)) (NN mantle)))))) (, ,) (CC and) (VP (ADJP (JJ mixed) (PP (IN into) (NP (DT the) (NN mantle)))) (PP (IN by) (NP (NP (NN subduction)) (PP (IN at) (NP (DT the) (NN ocean) (NNS trenches))))))))) (. .)))
Throughout the history of the earth, continental and oceanic crust have been created by magma formation in the deep earth's mantle, and mixed into the mantle by subduction at the ocean trenches.
(ROOT (S (NP (NNP Magma)) (VP (VBZ comes) (PP (IN toward) (NP (NP (NN earth) (POS 's)) (NN crust))) (PP (IN through) (NP (JJ mantle) (NNS plumes)))) (. .)))