( ( ( ( 200 million ) years ) ( ( ( 500 million ) years ) ( ( ( 600 million ) years ) ( ( ( 2 billion ) years ) ( These ( inclined ( earthquake zones ) ) ) ) ) ) ) ( ( are ( believed ( to ( ( define ( ( the positions ) ( of ( subducted plates ) ) ) ) ( where ( they ( plunge ( into ( ( the mantle ) ( beneath ( the ( overriding plate ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (QP (CD 200) (CD million)) (NNS years)) (PP (NP (QP (CD 500) (CD million)) (NNS years)) (NP (NP (QP (CD 600) (CD million)) (NNS years)) (PP (NP (QP (CD 2) (CD billion)) (NNS years)) (NP (NP (DT These)) (VP (VBN inclined) (NP (NN earthquake) (NNS zones)))))))) (VP (VBP are) (VP (VBN believed) (S (VP (TO to) (VP (VB define) (NP (NP (DT the) (NNS positions)) (PP (IN of) (NP (JJ subducted) (NNS plates)))) (SBAR (WHADVP (WRB where)) (S (NP (PRP they)) (VP (VBP plunge) (PP (IN into) (NP (NP (DT the) (NN mantle)) (PP (IN beneath) (NP (DT the) (VBG overriding) (NN plate))))))))))))) (. .)))
200 million years 500 million years 600 million years 2 billion years These inclined earthquake zones are believed to define the positions of subducted plates where they plunge into the mantle beneath the overriding plate.
(ROOT (S (NP (NNS Earthquakes)) (VP (VBP mark) (NP (NP (DT the) (NNS motions)) (PP (IN of) (NP (NP (VBG colliding) (NNS plates)) (CC and) (NP (NP (DT the) (NNS locations)) (SBAR (WHADVP (WRB where)) (S (NP (NNS plates)) (VP (VBP plunge) (PP (IN into) (NP (DT the) (NN mantle))))))))))) (. .)))