700 
 
 
 
 
 
600 
 
 
 
 
 
500 
production of copper, and production in Arizona. 
96 MINERALS YEARBOOK, 1967C 
 
 
400 
 
C 
 
0 
 
E 
 
L 300 
 
-J 
4 
> 
 
 
200 
 
 
 
 
 
I 00 
 
 
 
 
 
 
 
 
 
Figure 1.—Value of mine 
 
 
 
ranged from a low of 0.407 to 0.688 percent copper, averaging about 0.588
percent, slightly lower than the 1966 range of 0.417 to 0.708 percent, averaging
0.630 for more than 85 million tons of ore mined from the same pits. The
copper content of the 14.5 million tons of ores associated with alkaline
sedimentary rocks—the hornfels, argillites, and tacrites—ranged
from 0.482 to 0.782 percent, averaging 0.577. The copper ores having a low
copper content generally contained molybdenum as a byproduct— the molybdenum
offsetting the lower copper values. 
The mining of 68.3 million tons of 
total value of mineral 
970 
open-pit ore, the extension of existing pits, and the development of new
ore bodies required the removal of 253.7 million tons of waste and leach
material. Averaging about 2.4 to 1, stripping ratios (the ratio of waste
and leach material to ore) at the 14 major properties ranged from a low of
1.28 to 1 at the Inspiration (Thornton-Live Oak pits) mine in the Globe-Miami
district in the central part of the State, to a high of 4.4 to 1, at the
Lavender pit at Bisbee in the southeast. The higher stripping ratios reflected
development work in extending the pit limits at five of the principal properties—Pima,
Mission,