Look. I'm no expert myself. But this topic of overburden has been brought up a fair bit. I had to do some research myself because at first blush to the clueless such as myself, it makes sense. Thickness or thinness of deposit for open pits have differing designs. Less 'benches' for thin, more 'benches' for thick. This changes the cost of extraction significantly doesn't it?
Discl: this is a genuine question and not an attempt at being a smart alec.
