And that brings us back to the layout of the mines
This is a
typical cross-section for much of the Kennecott mine system. You see a main
incline tunnel with cross-cuts and drifts.
The incline runs along the contact zone, following that plane very closely.
Thus, most all of the ore pockets will occur above it, as you see here. The
broken mill ore area is actually an open stope. Ore is dug out from below,
blasting to the top of the vein and then mucking it out in what is known as the
shrinkage method of mining.
You will see a totally used-up stope at the top of this segment while the one at
the next level down is still being mined. This was very typical. The upper areas
were usually mined out first. The above
plan would be that same area looking down. As you can see the
drifts follow the edges of the ore occurrences, thus often defining the limits
of the ore vein. These diagrams were drawn up by William Douglass, the
superintendent during most of the 1920s at Kennecott.
