PLATE III. 



FiouRE 10 (page 32) represents in section tlie ore passing around and cutting off 

 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 in 

 it. Jackson Mine, Negaunee. 



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

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

 Mine, Negaunee. 



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

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

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

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

 figure its width has been greatly exaggerated compared with its length. Home Mine, 

 Cascade Range. 



