Plate XXIX.— THE ORE DEPOSITS. 



Cross-section of Section 16 mine, Lake Superior Iron Company. On the right is a V-shaped 

 trough made by the junction of a greenstone mass and a dike. The hard ore is between 

 these and below the Goodrich quartzite. On the left the hard ore again rests on soapstone, 

 which is upon and iuterstratified with jasper, and is overlain by the Goodrich quartzite. 

 Scale: 200'=1". 



Cross-section of the Barnuiu mine, showing hard ore resting either upon folded soapstone or 

 upon jasper, and overlain by soapstone. At the right of the figure is seen a layer of ore 

 between two soapstone dikes. Scale: 200' = 1 ". 



Longitudinal section of the mines operated by the Buffalo Mining Company, showing the 

 soft ore resting upon an impervious foot-wall of Siamo slate and grading upward into jasper. 

 Scale: 200' = 1". 



Cross-section of same, showing the slate folded into two troughs, which are shown by the 

 longitudinal section (fig. 3) to have a western pitch. 



