( ( ( Less dense ) ( felsic minerals ) ) ( ( ( dominate ( ( the ( igneous rocks ) ) ( of ( the ( upper crust ) ) ) ) ) ( while ( ( ( ( more ( dense mafic ) ) and ) ( ultramafic minerals ) ) ( dominate ( those ( of ( the ( lower crust ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (ADJP (RBR Less) (JJ dense)) (JJ felsic) (NNS minerals)) (VP (VBP dominate) (NP (NP (DT the) (JJ igneous) (NNS rocks)) (PP (IN of) (NP (DT the) (JJ upper) (NN crust)))) (SBAR (IN while) (S (NP (NP (JJR more) (JJ dense) (NN mafic)) (CC and) (NP (JJ ultramafic) (NNS minerals))) (VP (VBP dominate) (NP (NP (DT those)) (PP (IN of) (NP (DT the) (JJR lower) (NN crust)))))))) (. .)))
Less dense felsic minerals dominate the igneous rocks of the upper crust while more dense mafic and ultramafic minerals dominate those of the lower crust.
(ROOT (S (NP (JJ Felsic) (NNS igneous) (NNS rocks)) (VP (VP (VBP contain) (NP (JJ felsic) (NNS minerals))) (, ,) (VP (ADVP (RB typically)) (VBP contain) (NP (NN aluminum) (CC and) (NN sodium))) (CC and) (VP (VBP are) (ADJP (JJ high) (PP (IN in) (NP (NN silica)))))) (. .)))
Felsic igneous rocks contain felsic minerals, typically contain aluminum and sodium and are high in silica.