( ( During ( ( this time ) more ) ) ( ( explosive magmas ) ( ( were ( erupted ( ( showering ( the ( eastern ( ring plain ) ) ) ) ( with ( successive ( thick ( pumice layers ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN During) (ADVP (NP (DT this) (NN time)) (RBR more))) (NP (JJ explosive) (NNS magmas)) (VP (VBD were) (VP (VBN erupted) (S (VP (VBG showering) (NP (DT the) (JJ eastern) (NN ring) (NN plain)) (PP (IN with) (NP (JJ successive) (JJ thick) (NN pumice) (NNS layers))))))) (. .)))
During this time more explosive magmas were erupted showering the eastern ring plain with successive thick pumice layers.
(ROOT (S (NP (NP (DT The) (NN thickness)) (PP (IN of) (NP (NN magma)))) (VP (VBZ determines) (SBAR (IN whether) (S (NP (DT a) (JJ volcanic) (NN eruption)) (VP (MD will) (VP (VB be) (ADJP (JJ explosive))))) (CC or) (RB not))) (. .)))