BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 10, pp. 361-382, PLS. 35-41 NOVEMBER 5, 1899 



GRANITES OP SOUTHERN RHODE ISLAND AND CONNECT- 

 ICUT,^ WITH OBSERVATIONS ON ATLANTIC 

 COAST GRANITES IN GENERAL 



BY J. F. KEMP 



iRead before the Society December 30, 1898) 

 CONTENTS 



Page 



Outline of the geology of the area discussed . 362 



The granites 364 



Distribution 364 



Petrography 367 



General characteristics 367 



The Westerly gray granite 367 



The "Westerly red granite 368 



Accessory minerals in the Westerly granites ". 368 



Quonochontaug orbicular granite 369 



The Stony Creek types 369 



Intrusive nature of the granites ^ 370 



The contacts 370 



The basic inclusions .... 371 



The aplites and the pegmatites 372 



Chemical composition of the granites 375 



General remarks on the granites of tlie Atlantic seaboard 377 



Statistics of varieties 377 



Review by provinces or states 378 



New Brunswick 378 



Maine : 378 



New Hampshire 378 



Vermont ... 378 



Massachusetts 378 



Rhode Island and Connecticut 380 



New York 380 



New Jersey 380 



Pennsylvania ... 380 



Maryland 381 



*The writer became interested in the gi-anites liere described about ten years ago, while 

 spending summer vacations in Rhode Island. The observations have accumulated year by year 

 since then, and in their collection important assistance has been received from Gilbert van 

 Ingen, W. D. Matthew, and B. F. Hill, to whom acknowledgments are here made. 



LII— Bull. Geol. See. Am., Vol. 10, 1898 (361) 



