[Annals N. Y. Acad. Sci., Vol. XXIII, pp. 193-260, Pis. VIII-XV. 30 April, 



1914] 



THE MANHATTAN SCHIST OF SOUTHEASTERN NEW YORK 

 STATE AND ITS ASSOCIATED IGNEOUS ROCKS ' 



By Charles Reinhard Fettke 



(Presented hy title before the Academy, 1 December, 1913) 



CONTENTS 



Page 



Introduction 194 



Historical review 197 



Manhattan Schist 202 



Areal distribution 202 



Petrology 203 



Structural features 211 



Chemical composition 212 



Origin 213 



Associated igneous rocks 216 



Foliated basic intrusives 216 



Hornblende schist 216 



Actinolite and tremolite schists and associated types 219 



Harrison granodiorite gneiss 220 



Origin of hornblende schist and granodiorite gneiss 224 



Massive basic intrusives 227 



Cortlandt series 227 



Croton Falls hornblendite 228 



Diorite dikes in the vicinity of Bedford 231 



Serpentine 232 



Hornblende porphyrite 233 



Acidic intrusives 234 



Thomaston granite 234 



Aplites and pegmatites 235 



Bedford "augen" gneiss 239 



Occurrence of zeolites in Manhattan schist 243 



Summary 244 



Peekskill phyllite 245 



Poughquag-Wappinger-Hudson River series 246 



Poughquag quartzite 247 



Wappinger limestone 247 



Hudson River slates, phyllites and schists 248 



Historical geology 252 



Comparison of Inwood-Manhattan and Poughquag-Wappinger-Hudson 



River series 254 



Bibliography 258 



1 Manuscript received by the Editor, 1 December. 1913. (193) 



