THE 



CANADIAN NATURALIST 



AND 



^uavtcvlij fiutvnal of Science. 



ON THE GEOLOGICAL RELATIONS OF THE IRON 

 ORES OF NOVA SCOTIA. 



(^Read before the American Association for the Advancement 



of Science.) 



By J. W. Dawson, LL.D., F.R.S. 



The Iron Ores of Nova Scotia, long neglected, have recently 

 begun to attract the attention of capitalists to an extent in some 

 degree commensurate with their importance. The magnitude 

 and variety of the deposits, the great richness of the ores, their 

 proximity to the Atlantic and to great deposits of coal, are all 

 features which give them very great economic value, and must 

 eventually cause them to take no small part in contributing to 

 the iron supply of the w^orld. My purpose in the present paper 

 is, with the aid of recent researches in which I have been occu- 

 pied, to give a concise summary of the geological position and 

 mode of occurrence of the principal deposits, and more especially 

 of those facts which have been developed since the publication of 

 my '^ Acadian Geology." 



If we arrange these deposits in the first place under the two 

 heads of Beds conformable to the stratification and Veins, we 

 shall find that the former occupy three distinct geological hori- 

 zons — that of the Lower Helderberg or Ludlow in the upper 

 part of the Silurian, that of the Oriskany at the base of the De- 

 vonian, and that of the Lower and Middle Carboniferous. The 

 latter occur in altered rocks which may be assumed to be of 

 Vol. VII. I No. 2, 



