PYROPHYLLITIZATION, PINITIZATION, AND SILICIFI- 



CATIOX OF ROCKS AROUND CONCEPTION BAY, 



NEWFOUNDLAND 



A. F. BUDDINGTOX 

 Princeton University 



INTRODUCTION 



This paper embodies the results of a study of the regional and 

 local alterations which have affected a series of volcanic rocks 

 lying around the borders of the head of Conception Bay, on the 

 Avalon Peninsula of Newfoundland. The field work was accom- 

 plished by the writer as a member of the Princeton Geological 

 Expedition in Newfoundland during the summers of 1913 and 1914, 

 in connection with a general study of the pre-Cambrian rocks of 

 this region. The writer is indebted to the Geology Department 

 of Princeton University for facilities for studying these rocks in the 

 field and laboratory; to Dr. C. H. Smyth for supervision in the 

 preparation of the report; to Professor G. Yan Ingen for the 

 photographs with which this paper is illustrated and for his interest 

 in the work. The numbers used in this report refer to specimens 

 deposited in the museum of Princeton University. 



LOCATION 



Regional alterations, such as silicification and chloritization, 

 have affected the volcanic series wherever they outcrop, either in 

 the area here under consideration (Fig. 1), or at other points to the 

 north, such as Clarenville on Trinity Bay or Goose Arm on Bona- 

 vista Bay. The local alterations, comprising pyrophyllitization 

 and pinitization, have affected the volcanics only in limited areas; 

 the former being exhibited in a long narrow strip of rocks south 

 of Manuels and the latter in outcrops to the north of the mon- 

 zonite stock at Woodfords and in minute amounts associated with 

 the pyrophyllite rocks at Manuels. 



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