( ( ( eskers ( snake-shaped ridges ) ) ( made ( of ( ( sand and ) gravel ) ) ) ) ( ( deposited ( by ( streams ( that ( ( flowed ( through tunnels ) ) ( at ( ( the base ) ( of ( the glacier ) ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (NP (JJ eskers) (JJ snake-shaped) (NNS ridges)) (VP (VBN made) (PP (IN of) (NP (NN sand) (CC and) (NN gravel))))) (VP (VBD deposited) (PP (IN by) (NP (NP (NNP streams)) (SBAR (WHNP (WDT that)) (S (VP (VBD flowed) (PP (IN through) (NP (NNS tunnels))) (PP (IN at) (NP (NP (DT the) (NN base)) (PP (IN of) (NP (DT the) (NN glacier))))))))))) (: ;)))
eskers snake-shaped ridges made of sand and gravel deposited by streams that flowed through tunnels at the base of the glacier;
(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))))))))))) (. .)))