( Rocks ( ( are ( ( piled ( around ( the imprint ) ) ) ( to ( preserve it ) ) ) ) . ) )
(ROOT (S (NP (NNS Rocks)) (VP (VBP are) (VP (VBN piled) (PP (IN around) (NP (DT the) (NN imprint))) (S (VP (TO to) (VP (VB preserve) (NP (PRP it))))))) (. .)))
Rocks are piled around the imprint to preserve it.
(ROOT (S (NP (DT A) (NN mold)) (VP (VBZ is) (NP (NP (DT an) (NN imprint)) (PP (IN of) (NP (NP (DT an) (NN organism)) (VP (VBN left) (PP (IN in) (NP (NN rock)))))))) (. .)))