Hello.
I've started two quarries underground with five landmarks each - 4 to etch out the corners and another to add depth. They're about 64x32x39 each, starting at layer 44 or so. In *both* of them, the quarry accepted the landmarks fine and displayed the black and yellow outline like I wanted it to. Everything seems to be working perfectly, but when I check back later they've been mining from the surface down! I don't want huge, ugly holes in my landscape, so this has been kind of infuriating. They seem to be ignoring the bottom-most landmark for some reason. Adding more of them hasn't helped. Letting the quarry run without landmarks works just fine, however, but not in the pattern that I'd want.
To clarify, they've been destroying blocks from the top down - it hasn't laid it's framework down yet.
Help?
Here's some unnecessary pictures of the second attempt.
http://imgur.com/a/823M0