MODE OF OCCURRENCE 



395 



ings in seams and joint planes and encrusts some vein fillings beneath it. 

 The first vein crystallization is usually calcite in thin, almost transparent, 



Section of NeenahCltvj Q u a r r vj 

 S«' ' ScJo One, TncK= art. 



*o'o 



T- r 



-"^^-^ 



t; I I. (-Red) 



Wisconsin Drift 



G a 



en a 



L'l mc stone 



J 



M I nerali?ecl Zone 



Twrite 

 Calcite 

 rluorite 

 Ci a i en ct 



Dolomite 



Pvjrolusite 

 l:tO' Shhalcritel 



R./vi/B. 



FiGtJRE 1. — Section of Limestone Quarry at Neenah, Wisconsin 



rhombs, but often with scalenohedron combinations in the more open 

 vugs. The calcite v^as followed by a layer of iron pyrites, which as tiny 



