0 
 1945 950 1955 1960 1965 970 
 
 
Figure 1 —Value of iron-~ore shipments and total value of mineral production
in 
Minnesota. 
430 
600 
 
 
 
 
 
 
 
500 
 
 
 
 
 
 
 
400 
 
 
D 
 
0 
 
 
C 
.~ 300 
 
E 
 
uJ 
 
—J 
 
> 
 
200 
 
 
 
 
 
 
100 
MINERALS YEARBOOK, 1967