( ( Overlying ( these ( ancient rocks ) ) ) ( ( ( ( ( are , ) successively ) , ) ( sediments ( of ( ( ( the ( Cambrian ( , ( Ordovician ( , ( Silurian ( , ( Devonian ( , ( Mississippian ( , ( Pennsylvanian , ) ) ) ) ) ) ) ) ) ) ) ) and ) ( ( Permian periods ) ( of ( the ( Paleozoic era ) ) ) ) ) ) ) ) . ) )
(ROOT (S (S (VP (VBG Overlying) (NP (DT these) (JJ ancient) (NNS rocks)))) (VP (VBP are) (, ,) (ADVP (RB successively)) (, ,) (NP (NP (NNS sediments)) (PP (IN of) (NP (NP (DT the) (NNP Cambrian) (, ,) (NNP Ordovician) (, ,) (NNP Silurian) (, ,) (NNP Devonian) (, ,) (NNP Mississippian) (, ,) (NNP Pennsylvanian) (, ,)) (CC and) (NP (NP (JJ Permian) (NNS periods)) (PP (IN of) (NP (DT the) (JJ Paleozoic) (NN era)))))))) (. .)))
Overlying these ancient rocks are, successively, sediments of the Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, and Permian periods of the Paleozoic era.
(ROOT (S (NP (NP (DT The) (JJ first) (NN period)) (PP (IN of) (NP (DT the) (JJ paleozoic) (NN era)))) (VP (VBD was) (VP (VBN called) (NP (NN cambrian)))) (. .)))