| The three parts of this thesis have different focuses. Part I covers the bedrock geology of parts of the Peach Lake and Brewster quadrangles (New York - Connecticut). New interpretations of the stratigraphy, structural development, and metamorphic history of the northeastern Manhattan Prong are proposed. In Part II, a compilation of isotopic data from the north-central Appalachians is used to define five fundamental basement blocks (two juvenile, three of ancient continental crust). Part III builds upon compiled geologic data to infer the timing of the accretion of these blocks, and to model the Acadian orogeny.;Part I presents a newly recognized, rift-related Eocambrian unit, the Ned Mountain Formation (NMF). The NMF consists of bimodal metavolcanic rocks, meta-arkoses, meta-wackes, and calc-silicate rocks which crop out between the Grenvillian Fordham Gneiss and the Cambro-Ordovician Inwood Marble. The NMF is subdivided into a graphitic Basal Member, a Volcaniclastic Member (including "Pound Ridge granite"), Wacke Member, and an uppermost Calc-Silicate Member (including "Lowerre Quartzite"). NMF strata are compositionally distinct in many respects from rocks of other formations. Reconnaissance transects outside the study area confirm persistence of the NMF over a large area.;Six episodes of Paleozoic deformation are recognized in the study area. The Hartland terrane was emplaced over the Manhattan Prong during (Taconian) D;Three principal metamorphic events are recognized: granulite-facies M;The model developed in Parts II and III places the Manhattan Prong into regional geological context. |
