CONTENTS. 



Page 

 INTRODUCTION 1 



THE IRON DISTRICT 1-76 



Historical 1-26 



Historical Summary 26, 27 



]\Iethods of Observation 27, 28 



The Jasper and Iron Ore 28-36 



The Basic Intrusive Rocks, Schists, and Felsite . . 36-49 



" Soft Hematites " 49-52 



Granite, Gneiss, and Quartzite 52-60 



Potsdam Sandstone 60 



Peridotite and Serpentine 60-66 



General Discussion and Results 66-76 



THE COPPER DISTRICT 76-132 



Historical 76-107 



Historical Summary 107-109 



The Traps . . . , 109-113 



The Sandstones and Conglomerates 113-122 



The Veins and Copper DntosiTS 123-127 



Conclusions 127-132 



BIBLIOGRAPHY 133-157 



DESCRIPTION OF THE PLATES 159-164 



