BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 2, pp. 125-140 February 5, i89i 



THE NICKEL AND COPPER DEPOSITS OF SUDBURY 

 DISTRICT, CANADA. 



BY ROBERT BELL, B. A. SC, M. D., LL. D., ASSLSTANT DIRECTOR OF 

 THE GEOLOGICAL SURVEY OF CANADA. 



With an Appendix on 



THE SILICIPIED GLASS-BRECCIA OF VERMILION RIVER, SUDBURY 



DISTRICT. 



BY GEORGE H. WILLIAMS. 



[Read before the Society December 31, 1890.) 



CONTENTS. 



Page. 



Introduction 125 



The Geology of the District 126 



The Ores and their Associations 131 



Mode of Occurrence of the Ores 133 



The Genesis of the Ores 135 



Extent and Associations of the Ores 136 



The Silicified Glass-Breccia of Vermilion River, Sudbur}- District 138 



Introduction. 



The town of Sudbury, a creation of the Canadian Pacific railway, is situ- 

 ated in the backwoods of Ontario, thirty-six miles north of the mouth of 

 French river, on Lake Huron. Parts of the surrounding country are tol- 

 erably level, but in a general way this region maybe said to be hilly. Some 

 sections are very broken and rugged, while in others rocky ridges alternate 

 with s\vara2:)S or alluvial intervals. Occasional tracts of land are fit for cul- 

 tivation, but, as a rule, where the surface does not consist of rock or swamp 

 it is much encumbered with bowlders. At one time the district supported 

 large quantities of white-pine timber, but forest fires at difierent periods have 

 destroyed the greater part of it and inferior kinds of wood are now growing 



XIX— Bull. Geol. Son. Am., Vol. 2. 1890. (^--j) 



