IIG ANNALS NEW YORK ACADEMY OF SCIENCES 



Page 



Virginia 144 



West Virginia 145 



Pennsylvania 145 



New Yorli 146 



Nova Scotia 147 



Artesian conditions in the ("linton deposits 147 



Porous layers i 148 



Impervious layers 148 



Marine artesian slopes 149 



Infiltration of meteoric waters 149 



Ore conditions resulting from artesian slopes 150 



Depth of deposits 150 



Extent of deposit down dip 151 



Wide distribution of deposits 151 



Occurrence of oolitic and fossiliferous ore 151 



Variations in chemical composition 151 



Variations in texture 152 



Variations in richness 152 



Artesian replacement theory as applied to other horizons 152 



Deposits of Wabana, Newfoundland 153 



Deposits of Mira Valley, Cape Breton. N. S 153 



General summary and conclusions 153 



Part III. Bibliography 156 



Introduction 



The great economic importance of interbedded iron ore deposits has 

 been recognized for many years. Two types of these ores may be cited 

 as notable examples : first, and possibly most important, are the Clinton 

 liematites extending along the ^Appalachian system of mountains for 

 nearly two thousand miles and having their greatest development in the 

 Birmingham district, Alabama; second, the Wabana hematite deposits, 

 on and near Belle Isle, Newfoundland. 



The great extent, commercial importance and scientific interest of 

 these Paleozoic interbedded iron ore deposits has long made them a sub- 

 ject of painstaking exploration and study ; the extensive development of 

 them that has taken place during the last fifty years, and more especially 

 within the last ten years, has made it possible to gather together a large 

 amount of information of a detailed and accurate nature that under 

 other conditions would have been impossible. 



Underground mining has largely taken the place of earlier open-cut 

 methods. At Wabana, for example, the ore is now being mined under 

 the sea at a distance of two miles from the original open-cut workings. 



