( ( ( The ( red color ) ) ( of ( the soil ) ) ) ( ( ( is ( due ( to ( ( the precipitation ) ( of ( iron ( ( oxides and ) hydroxides ) ) ) ) ) ) ) ( in ( the ( B horizon ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ red) (NN color)) (PP (IN of) (NP (DT the) (NN soil)))) (VP (VBZ is) (ADJP (JJ due) (PP (TO to) (NP (NP (DT the) (NN precipitation)) (PP (IN of) (NP (NN iron) (NNS oxides) (CC and) (NNS hydroxides)))))) (PP (IN in) (NP (DT the) (NNP B) (NN horizon)))) (. .)))
The red color of the soil is due to the precipitation of iron oxides and hydroxides in the B horizon.
(ROOT (S (NP (NP (NNP Iron)) (PP (IN in) (NP (DT the) (NN soil)))) (VP (VBZ causes) (S (NP (NNS mars)) (VP (TO to) (VP (VB look) (ADJP (JJ red)))))) (. .)))