( ( If ( ( the meteorite ) ( had ( ( impacted ( in ( areas ( of ( calcium carbonate ) ) ) ) ) ( -LRB- ( ( as ( in ( the ( Cretaceous seabed ) ) ) ) -RRB- ) ) ) ) ) ) ( ( ( great amounts ) ( of ( carbon dioxide ) ) ) ( ( would ( have ( been ( released ( into ( the atmosphere ) ) ) ) ) ) . ) ) )
(ROOT (S (SBAR (IN If) (S (NP (DT the) (NN meteorite)) (VP (VBD had) (VP (VBN impacted) (PP (IN in) (NP (NP (NNS areas)) (PP (IN of) (NP (NN calcium) (NN carbonate))))) (PRN (-LRB- -LRB-) (PP (RB as) (IN in) (NP (DT the) (JJ Cretaceous) (NN seabed))) (-RRB- -RRB-)))))) (NP (NP (JJ great) (NNS amounts)) (PP (IN of) (NP (NN carbon) (NN dioxide)))) (VP (MD would) (VP (VB have) (VP (VBN been) (VP (VBN released) (PP (IN into) (NP (DT the) (NN atmosphere))))))) (. .)))
If the meteorite had impacted in areas of calcium carbonate( as in the Cretaceous seabed) great amounts of carbon dioxide would have been released into the atmosphere.
(ROOT (S (PP (IN During) (NP (DT the) (JJ early) (NN paleozoic))) (, ,) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN atmosphere)))))) (VP (VBD was) (ADJP (RB much) (JJR greater)) (PP (VBN compared) (PP (TO to) (NP (NN today))))) (. .)))