( Esker ( ( ( ( ( A ( serpentine ridge ) ) ( of ( ( roughly stratified ) ( ( gravel and ) sand ) ) ) ) ( that ( ( ( was ( deposited ( by ( ( a stream ) ( flowing ( ( ( in or ) beneath ) ( ( the ice ) ( of ( a ( ( ( stagnant or ) retreating ) glacier ) ) ) ) ) ) ) ) ) ) and ) ( was ( left ( behind ( when ( ( the ice ) melted ) ) ) ) ) ) ) ) ( -LRB- ( ( ( ( ( Bates and ) Jackson ) , ) 1984 ) -RRB- ) ) ) . ) )
(ROOT (S (NP (NNP Esker)) (VP (NP (NP (DT A) (JJ serpentine) (NN ridge)) (PP (IN of) (NP (ADJP (RB roughly) (JJ stratified)) (NN gravel) (CC and) (NN sand))) (SBAR (WHNP (WDT that)) (S (VP (VP (VBD was) (VP (VBN deposited) (PP (IN by) (NP (NP (DT a) (NN stream)) (VP (VBG flowing) (PP (IN in) (CC or) (IN beneath) (NP (NP (DT the) (NN ice)) (PP (IN of) (NP (DT a) (ADJP (JJ stagnant) (CC or) (JJ retreating)) (NN glacier)))))))))) (CC and) (VP (VBD was) (VP (VBN left) (PP (IN behind) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN ice)) (VP (VBD melted))))))))))) (PRN (-LRB- -LRB-) (NP (NNP Bates) (CC and) (NNP Jackson)) (, ,) (NP (CD 1984)) (-RRB- -RRB-))) (. .)))
Esker A serpentine ridge of roughly stratified gravel and sand that was deposited by a stream flowing in or beneath the ice of a stagnant or retreating glacier and was left behind when the ice melted (Bates and Jackson, 1984).
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN esker)) (VP (VBZ is) (NP (NP (DT a) (JJ winding) (NN ridge)) (PP (IN of) (NP (NN sand))) (SBAR (S (VP (VBD deposited) (PP (IN by) (NP (NP (DT a) (NN stream)) (PP (IN of) (NP (NP (NN meltwater)) (VP (VBN called))))))))))) (. .)))