For those of you that don't know why the ( __l'''l__ ) arch and base line are used to symbolise a mine.
Mineral ores come from molten rock, forced up through the earth's crust. This molten rock is boiling, and the minerals are swirling around and not having the chance to settle back down, they get trapped as the molten rock cools quikly. The places with the most preasure and that holds the most mineral ore, is at the center or tip. This center/tip is Identified by what is known to some as "The finger of God" and looks like a multitude of "arches" one inside the other, something like the way a marble cake looks. Along with the arch, there is also a fault zone at the base. Mostly all heavy minerals are found within this Arch/swirl/finger is and near by.
These places don't always look like this. It would all depend on what part is showing from the rock.
I have added a pic near to the Apache trail, I'm sure you can see where it's from. the purple is the symbol and the yellow is the rock itself.