( ( Less ( dense crust ) ) ( ( rises ( ( higher ( -LRB- ( ( continental crust ) -RRB- ) ) ) ( than ( does ( ( more ( dense crust ) ) ( -LRB- ( ( ocean crust ) -RRB- ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (RBR Less) (JJ dense) (NN crust)) (VP (VBZ rises) (ADVP (ADVP (RBR higher)) (PRN (-LRB- -LRB-) (NP (JJ continental) (NN crust)) (-RRB- -RRB-)) (SBAR (IN than) (SINV (VP (VBZ does)) (NP (NP (JJR more) (JJ dense) (NN crust)) (PRN (-LRB- -LRB-) (NP (NN ocean) (NN crust)) (-RRB- -RRB-))))))) (. .)))
Less dense crust rises higher (continental crust) than does more dense crust (ocean crust).
(ROOT (S (NP (NNP Gabbro)) (VP (VBZ is) (NP (NP (DT a) (JJ dark) (JJ dense) (NN rock)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (VP (VB be) (VP (VBN found) (PP (IN in) (NP (DT the) (JJ oceanic) (NN crust)))))))))) (. .)))
Gabbro is a dark dense rock that can be found in the oceanic crust.