PLATE III. 



r 



FiaiTKE 10 (page 32) represents in section the ore passing around and cutting olT 

 a portion of the schist, some six feet in length, from the main body. The ore at the 

 lower portion of the figure was then being mined, the schist forming a horse iu 

 it. Jackson Mine, Negaunee. 



FiouKE 12 (page 32) shows the relations of ore, wliich was then being mined, to 

 its overlying schist. This represents a section some twenty feet in length. Jackson 

 Mine, Negf,unoe. 



FiGriiE 13 (page 32) represents a section of a jasper dike in a sandstone. The dike 

 is of irregular width, and approximately follows the stratification of the sandstone in 



its main course. It sends projections in places out across the lamlnai, breaking, con- 

 torting, and indurating them. The dike is some fifteen feet in length, and in the 

 figure its width has bocu greatly exaggerated compared with its lengtli. Home Mine, 



Cascade Range. 



