VOLUME XXVIT NUMBER 2 



THE 



JOURNAL OF GEOLOGY 



FEBRUARY-MARCH igig 



SOME STRATIGRAPHIC AND STRUCTURAL FEATURES 



OF THE PRE-CAMBRIAN OF NORTHERN 



QUEBEC^ 



H. C. COOKE 



Geological Survey of Canada, Ottawa 



PART I 

 INTRODUCTION 



In the present paper the writer will describe briefly the known 

 geology of that part of northern Quebec whose four corners are 

 the north end of Lake Timiskaming, James Bay, Lake Mistassini, 

 and Lake St. John, with the particular object of setting forth the 

 stratigraphic sequence and age relations of its ancient volcanic 

 and sedimentary rocks. 



This region is of especial interest on account of its development 

 of rocks of early pre-Cambrian age. The relations existing between 

 these rocks are shown very fully and satisfactorily, and their 

 examination enlarges our knowledge of pre-Cambrian history and 

 introduces corresponding changes in nomenclature. Structural 

 work in this region, as described in this paper, demonstrates (i) a 

 uniform sequence of extrusion in the lavas, termed the Abitibi 



^ Published by permission of the Geological Survey of Canada. 



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