Q 



, w York State Museum Bulletin 



17 O. ! as second - class matter November 27, 1915, at the Post Office at Albany, New York, 



. under the act of August 24, 1912 



Published monthly by The University of the State of New York 



No. 20 1 



ALBANY, N. Y. 



SEPTEMBER i, 1917 



The University of the State of New York 

 New York State Museum 



UC-NRLF 



M. CLARKE, DIRECTOR 



B 3 Dfi3 fififi 

 GENESIS OF THE ZINC ORES OF THE EDWARDS 



DISTRICT, ST LAWRENCE COUNTY, N. Y. 



BY C. H. SMYTH JR 



PAGE 



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 II 



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 



Minr-Jei8-i5oo 



