Q 



N82X J York State Museum Bulletin 



NH 



second-class matter November 27, 1915, at the Post Office at Albany, New York, 

 under the act of August 24, 1912 



^ ablished monthly by The University of the State of New York 



No. 201 



ALBANY, N. Y. 



September i, 19 17 



he University of the State of New York 

 New York State Museum 



John M. Clarke, Director 



GENESIS OF THE ZINC ORES OF THE EDWARDS 

 DISTRICT, ST LAWRENCE COUNTY, N. Y. 



By C. H. SMYTH Jr 



Introduction 7 



Nature of the problem 8 



Resume of geological features 8 



Geological history of the ore 



deposits •. 10 



Appearance and characteristics of 



the ores 11 



General discussion of meta- 



morphism 13 



Metamorphism and the ore 



deposits 14 



PAGE 



Order of sulphide deposition 20 



Relation of sulphides to secondary 



silicates 22 



Sphalerite of later deposition 26 



Comparison of ores with zinc ores 



of other regions ; . 29 



Chemistry of ore deposition 33 



Index 41 



ALBANY 



THE UNIVERSITY OF THE STATE OF NEW YORK 

 1918 

 Miiir-Jei8-i50o 



