( ( ( ( gravity prospecting ) - ) ( ( ( Mapping force ) ( of ( gravity ( at ( different places ) ) ) ) ) ( to ( ( determine differences ) ( in ( ( specific gravity ) ( of ( ( ( ( rock masses ) and ) ( , ( ( through this ) , ) ) ) ( distribution ( of ( masses ( of ( different ( specific gravity ) ) ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NN gravity) (NN prospecting)) (: -) (NP (NP (JJ Mapping) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (PP (IN at) (NP (JJ different) (NNS places))))) (S (VP (TO to) (VP (VB determine) (NP (NNS differences)) (PP (IN in) (NP (NP (JJ specific) (NN gravity)) (PP (IN of) (NP (NP (NN rock) (NNS masses)) (CC and) (PRN (, ,) (PP (IN through) (NP (DT this))) (, ,)) (NP (NP (NN distribution)) (PP (IN of) (NP (NP (NNS masses)) (PP (IN of) (NP (JJ different) (JJ specific) (NN gravity)))))))))))))) (. .)))
gravity prospecting - Mapping force of gravity at different places to determine differences in specific gravity of rock masses and, through this, distribution of masses of different specific gravity.
(ROOT (S (NP (NNP Gravity)) (VP (VBZ causes) (S (NP (NNS rocks)) (VP (TO to) (VP (VB roll) (ADVP (RB downhill)))))) (. .)))