( ( As ( ( the glaciers ) melted ) ) ( , ( ( the ( eroded sediments ) ) ( ( ( ( were ( ( left behind ) ( as ( piles ( of debris ) ) ) ) ) or ) ( deposited ( in streams ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN As) (S (NP (DT the) (NNS glaciers)) (VP (VBD melted)))) (, ,) (NP (DT the) (JJ eroded) (NNS sediments)) (VP (VP (VBD were) (VP (VBN left) (PRT (RP behind)) (PP (IN as) (NP (NP (NNS piles)) (PP (IN of) (NP (NN debris))))))) (CC or) (VP (VBD deposited) (PP (IN in) (NP (NNP streams))))) (. .)))
As the glaciers melted, the eroded sediments were left behind as piles of debris or deposited in streams.
(ROOT (S (NP (NNS Glaciers)) (VP (VB deposit) (NP (PRP$ their) (NN sediment)) (SBAR (WHADVP (WRB when)) (S (NP (PRP they)) (VP (VB melt))))) (. .)))