( ( To ( evaluate ( ( the proportion ) ( of ( felsic minerals ) ) ) ) ) . )
(ROOT (S (VP (TO To) (VP (VB evaluate) (NP (NP (DT the) (NN proportion)) (PP (IN of) (NP (JJ felsic) (NNS minerals)))))) (. .)))
To evaluate the proportion of felsic minerals.
(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.