( ( a -RRB- ) ( A ( ( ( ( ( ( buried ( ( fault or ) fracture ) ) ( with ( older rocks ) ) ) above ) and ) ( ( younger rocks ) below ) ) . ) ) )
(ROOT (S (LST (LS a) (-RRB- -RRB-)) (NP (NNP A)) (VP (VP (VBD buried) (NP (NN fault) (CC or) (NN fracture)) (PP (IN with) (NP (JJR older) (NNS rocks))) (PP (IN above))) (CC and) (VP (NP (JJR younger) (NNS rocks)) (ADVP (RB below)))) (. .)))
a) A buried fault or fracture with older rocks above and younger rocks below.
(ROOT (S (NP (DT A) (NN fault)) (VP (VBZ is) (NP (NP (DT the) (NN fracture)) (VP (VBN caused) (SBAR (WHADVP (WRB when)) (S (NP (NP (NNS rocks)) (PP (IN on) (NP (DT both) (NNS sides)))) (VP (VBP move))))))) (. .)))