TABLE OF CONTENTS 



PAGE 



PREFACE iii 



LIST OF ILLUSTRATIONS xi 



LIST OF ABBREVIATIONS... xv 



PART I. INTRODUCTORY. 



CHAPTER I. GENERAL GEOLOGICAL FACTS AND PRINCIPLES. 



The two standpoints of geology, 3-4 ; the scheme of classifica- 

 tion, 4-5 ; classification of rocks, 6 ; brief topographical survey of 

 the United States, 6-7 ; brief geological outline, 7-10 ; the forms 

 assumed by rock masses, 10, 11 1-11 



CHAPTER II. ON THE FORMATION OF CAVITIES IN ROCKS. 



By local contraction, 12, 13 ; by more extensive movements, 

 13-17 ; faults, 17-20 ; secondary modifications of cavities, 20-22.. 12-22 



CHAPTER III. THE MINERALS IMPORTANT AS ORES ; THE GANGUE 

 MINERALS, AND THE SOURCES WHENCE BOTH ARE DERIVED. 



The minerals, 23 ; source of the metals, 23-27 23-27 



CHAPTER IV. ON THE FILLING OF MINERAL VEINS. 



Resume, 28; methods of filling, 28, 29; ascension by infiltra- 

 tion, 29, 32 ; lateral secretion, 30, 31 ; replacement, 33, 34 28-34 



CHAPTER V. ON CERTAIN STRUCTURAL FEATURES OF MINERAL VEINS. 



Banded structure, 35-37 ; clay selvage, 37 ; pinches, swells, and 



lateral enlargements, 37 ; changes in the character of the vein 



filling, 38 ; secondary alteration of the minerals in veins, 38-40 ; 



electrical activity, 40, 41 35-11 



CHAPTER VI. THE CLASSIFICATION OF ORE DEPOSITS, A REVIEW AND 

 A SCHEME BASED ON ORIGIN. 



Statement of principles, 42-44 ; schemes involving only the 

 classification of veins by Von Weissenbach, 44 ; Von Cotta, 44, 45 ; 

 Le Conte, 45 ; general schemes based on form : Von Cotta and 



